[CORE-3202] Fix NUMBER not compatible with H2

[nick318]

Impact

• Bug fix (non-breaking change which fixes expected existing functionality)
• Enhancement/New feature (adds functionality without impacting existing logic)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

Fixes NUMBER not compatible with H2 in PostreSql compatibility mode (or suggested for h2 in general).
Full description is here - https://liquibase.jira.com/browse/CORE-3202

As H2 supports numeric, we can use it as a default type as for others DBs

[github-actions]

Unit Test Results

  4 620 files  ±  0    4 620 suites  ±0   34m 32s ⏱️ + 2m 32s
  4 597 tests +  3    4 378 ✔️  -   1     219 💤 +4  0 ❌ ±0 
54 336 runs  +36  49 312 ✔️ +32  5 024 💤 +4  0 ❌ ±0 

Results for commit 668ac01. ± Comparison against base commit a2dde51.

♻️ This comment has been updated with latest results.

[nvoxland]

Code review and test results:

Things to be aware of:

• Code makes sense and is isolated to h2
• Test harness "diff" test is failing for what seems to be other reasons

Things to worry about:

• Nothing

[XDelphiGrl]

• PR fixes a long-standing H2 bug where explicitly defined 'numeric' datatype in changesets was replaced with 'number', which is unsupported on H2.
  • An example of a changeset that was generating invalid SQL and now produces valid SQL containing NUMERIC is:

- changeSet:
      changes:
      - addColumn:
          tableName: talent
          columns:
          - column:
              name: rate
              type: numeric(20, 2)

• New unit tests added for H2.

[KushnirykOleh]

Investigated test-harness build failure. It is failing due to this branch being outdated, bringing latest master changes should fix the issue. Or this failure can be ignored as we already know the reason.
I'll take care of test-harness part after that