Add GeneratedValue strategy to generate ID automaticially

[hantsy]

Like the JPA and Micronaut Data Jdbc/R2dbc, add JPA @GeneratedValue(strategy) similar feature to generate ID automatically before inserting.

[DiegoKrupitza]

I think that @GeneratedValue depends on issue #1171

[schauder]

@DiegoKrupitza I'm not sure how these would depend on each other.
Of course, there might be generators that depend on some database infrastructure, but many won't and either way one can still require the user to ensure that infrastructure is there.

[cooperlyt]

is there no any update?