[Enhancement] Support execute-only flag for performance test

[Seaven]

Why I'm doing:

What I'm doing:

don't send sql result to client, for test accurate performance

MySQL td> set enable_execution_only=false
Query OK, 0 rows affected
Time: 0.021s
MySQL td> select * from t1;
+--------+--------+-----------+
| v1     | v2     | a1        |
+--------+--------+-----------+
| <null> | <null> | ["a"]     |
| 1      | 1      | ["1","2"] |
| 1      | <null> | []        |
| 2      | 2      | ["3","4"] |
| 2      | <null> | []        |
| 3      | <null> | []        |
| 4      | <null> | []        |
| 5      | <null> | <null>    |
+--------+--------+-----------+
8 rows in set
Time: 0.099s
MySQL td> set enable_execution_only=true
Query OK, 0 rows affected
Time: 0.004s
MySQL td> select * from t1;
+----+----+----+
| v1 | v2 | a1 |
+----+----+----+
+----+----+----+
0 rows in set
Time: 0.059s
MySQL td>

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

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 4 / 4 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	com/starrocks/qe/SessionVariable.java	2	2	100.00%	[]
🔵	com/starrocks/qe/StmtExecutor.java	2	2	100.00%	[]

[github-actions]

[BE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)