[Feature] [Connector-V2 E2E] Add mysql and postgres e2e test and bug fix

[ic4y]

Purpose of this pull request

Check list

Add mysql and postgres e2e test

• [x] Code changed are covered with tests, or it does not need tests for reason:
• [x] If any new Jar binary package adding in your PR, please add License Notice according New License Guide
• [x] If necessary, please update the documentation to describe the new feature. https://github.com/apache/incubator-seatunnel/tree/dev/docs

[ic4y]

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