HHH-19365 GaussDB Dialect Support

[liubao68]

As discussed, move new Dialect Support to community.

see old PR to core #10093

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https://hibernate.atlassian.net/browse/HHH-19365

[liubao68]

Everything is ready for review

[liubao68]

Build and test:

./docker_db.sh gaussdb
./gradlew build -Pdb=gaussdb -DdbHost=localhost:8000

BUILD SUCCESSFUL in 25m 56s

[quaff]

IMHO, the GaussDB Dialect should extends PostgreSQL Dialect to reuse code as possible, not to duplicate all related sources.

[liubao68]

IMHO, the GaussDB Dialect should extends PostgreSQL Dialect to reuse code as possible, not to duplicate all related sources.

Actually, GaussDB has many different features than PostgreSQL and now the tested mode is Oracle compatibility . In future, GaussDB will not compatible with PostgreSQL but with OpenGauss. And a separation of code may help us testing and add new features.

Your suggestion is quite good for less code duplication. But there are some potential risks. For example, a contributor modified PostgreSQL related code will influence GaussDB, however, Hibernate community is not respnosible for fixing problems in community dialect.