[Tool] fix meta_tool.sh

[kevincai]

• use start_backend.sh to invoke meta_tool for common env settings
• support showing help message if no options provided for meta_tool
• set FLAGS_operation to empty by default, so the usage message can be shown if the user doesn't provide any parameter when invoking the tool

Why I'm doing:

What I'm doing:

Fixes #issue

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 3.3
  • 3.2
  • 3.1
  • 3.0
  • 2.5

[kevincai]

An example of the output when running meta_tool without any parameter

meta_tool: 
  meta_tool is the StarRocks BE Meta tool.
    [CAUTION] Stop BE first before using this tool if modification will be made.

  Usage:
    get_meta:
      meta_tool --operation=get_meta --root_path=</path/to/storage/path> --tablet_id=<tabletid> [--schema_hash=<schemahash>]
    load_meta:
      meta_tool --operation=load_meta --root_path=</path/to/storage/path> --json_meta_path=<path>
    delete_meta:
      meta_tool --operation=delete_meta --root_path=</path/to/storage/path> --tablet_id=<tabletid> [--schema_hash=<schemahash>]
      meta_tool --operation=delete_meta --root_path=</path/to/storage/path> --table_id=<tableid>
      meta_tool --operation=delete_meta --tablet_file=<file_path>
    delete_rowset_meta:
      meta_tool --operation=delete_rowset_meta --root_path=</path/to/storage/path> --tablet_uid=<tablet_uid> --rowset_id=<rowset_id>
    delete_persistent_index_meta:
      meta_tool --operation=delete_persistent_index_meta --root_path=</path/to/storage/path> --tablet_id=<tabletid>
      meta_tool --operation=delete_persistent_index_meta --root_path=</path/to/storage/path> --table_id=<tableid>
    compact_meta:
      meta_tool --operation=compact_meta --root_path=</path/to/storage/path>
    get_meta_stats:
      meta_tool --operation=get_meta_stats --root_path=</path/to/storage/path>
    ls:
      meta_tool --operation=ls --root_path=</path/to/storage/path>
    show_meta:
      meta_tool --operation=show_meta --pb_meta_path=<path>
    show_segment_footer:
      meta_tool --operation=show_segment_footer --file=</path/to/segment/file>
    dump_segment_data:
      meta_tool --operation=dump_segment_data --file=</path/to/segment/file>
    dump_column_size:
      meta_tool --operation=dump_column_size --file=</path/to/segment/file>
    print_pk_dump:
      meta_tool --operation=print_pk_dump --file=</path/to/pk/dump/file>
    dump_short_key_index:
      meta_tool --operation=dump_short_key_index --file=</path/to/segment/file> --key_column_count=<2>
    calc_checksum:
      meta_tool --operation=calc_checksum [--column_index=<index>] --file=</path/to/segment/file>
    check_table_meta_consistency:
      meta_tool --operation=check_table_meta_consistency --root_path=</path/to/storage/path> --table_id=<tableid>
    scan_dcgs:
      meta_tool --operation=scan_dcgs --root_path=</path/to/storage/path> --tablet_id=<tabletid>
    print_lake_metadata:
      cat <tablet_meta_file.meta> | meta_tool --operation=print_lake_metadata
    print_lake_txn_log:
      cat <tablet_transaction_log_file.log> | meta_tool --operation=print_lake_txn_log
    print_lake_schema:
      cat <tablet_schema_file> | meta_tool --operation=print_lake_schema
    lake_datafile_gc:
      meta_tool --operation=lake_datafile_gc --root_path=<path> --expired_sec=<86400> --conf_file=<path> --audit_file=<path> --do_delete=<true|false>
    

  Flags from /build/starrocks/be/src/tools/meta_tool.cpp:
    -audit_file (audit file path) type: string default: ""
    -column_index (column index) type: int32 default: -1
    -conf_file (conf file path) type: string default: ""
    -do_delete (do delete files) type: bool default: false
    -expired_sec (expired seconds) type: int64 default: 86400
    -file (segment file path) type: string default: ""
    -json_meta_path (absolute json meta file path) type: string default: ""
    -key_column_count (key column count) type: int32 default: 0
    -operation (valid operation: get_meta, flag, load_meta, delete_meta,
      delete_rowset_meta, show_meta, check_table_meta_consistency,
      print_lake_metadata, print_lake_txn_log, print_lake_schema) type: string
      default: ""
    -pb_meta_path (pb meta file path) type: string default: ""
    -root_path (storage root path) type: string default: ""
    -rowset_id (rowset_id) type: string default: ""
    -schema_hash (schema_hash for tablet meta) type: int32 default: 0
    -table_id (table id for table meta) type: int64 default: 0
    -tablet_file (file to save a set of tablets) type: string default: ""
    -tablet_id (tablet_id for tablet meta) type: int64 default: 0
    -tablet_uid (tablet_uid for tablet meta) type: string default: ""

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[BE Incremental Coverage Report]

❌ fail : 0 / 13 (00.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	be/src/tools/meta_tool.cpp	0	13	00.00%	[121, 172, 176, 177, 1027, 1034, 1035, 1216, 1217, 1227, 1228, 1259, 1260]

[kevincai]

@Mergifyio backport branch-3.3 branch-3.2 branch-3.1

[mergify]

backport branch-3.3 branch-3.2 branch-3.1

✅ Backports have been created

• #45806 [Tool] fix meta_tool.sh (backport #45587) has been created for branch branch-3.3
• #45807 [Tool] fix meta_tool.sh (backport #45587) has been created for branch branch-3.2 but encountered conflicts
• #45808 [Tool] fix meta_tool.sh (backport #45587) has been created for branch branch-3.1 but encountered conflicts