Java base driver compatibility tests infrastructure

[alex-dukhno]

• Configure GH action to run on pull request [Java base driver compatibility] configure GH action to run on pull request #420
• Configure GH action matrix for different connection parameters [Java base driver compatibility] configure GH action matrix for different connection parameters #421 https://jdbc.postgresql.org/documentation/head/connect.html that can influence execution flow
• Investigate messages flow with pure Java JDBC [Java base driver compatibility] Investigate messages flow with pure Java JDBC #422
• Investigate categories of connection parameters that should be covered with tests e.g. sslmode [Java base driver compatibility] Investigate categories of connection parameters that should be covered with tests #423
• Investigate how to run pgjdbc tests against database see https://github.com/pgjdbc/pgjdbc/blob/master/TESTING.md [Java base driver compatibility] Investigate how to run pgjdbc tests against database #433