[FLINK-35713][common] Support set parallelism in source and sink
https://issues.apache.org/jira/browse/FLINK-35713
@yuxiqian I found that the PR-3438 has been closed, could you please take a look?
ping @leonardBang
@ChaomingZhangCN Could you rebase this PR to latest master branch as it bumped junit version to junit5 for all tests?
Minor suggestion: shall we pick MySqlToPaimonE2eITCase and FlinkParallelizedPipelineITCase to be executed with different source / sink parallelism? I believe they could cover most parallelism-aware operators (flush event alignment, 2-PC sinks, and schema operators).
CI failed...
@leonardBang PTAL~
@ChaomingZhangCN Could you fix the conflicts?