HHH-18998 annotation-based config for UserType

[gavinking]

[Please describe here what your change is about]

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https://hibernate.atlassian.net/browse/HHH-18998

[yrodiere]

@gavinking was there any concern about this? Just wanting to discuss it with someone else maybe?

[gavinking]

If I recall correctly, I was not completely happy with it.

[yrodiere]

I will schedule discussing this with the team

[sebersole]

I like it!

[sebersole]

I think I may be missing the "config" aspect though? I was assuming you'd do something like:

@Entity
class Thing {
    ...
    @Stuff(config="abc")
    Stuff stuff;
}

@Type(StuffType.class)
@interface Stuff {
    String config();
}

class StuffType implements UserType<Stuff> {
    /** Constructor injection  */
    StuffType(Stuff annotation) {...}

    /** Or contract injection */
    void configure(Stuff annotation) { ... }
}

But I'm not seeing the injection bit.