Add support for repeatable annotations

[YangSiJun528]

Resolves issue #1624 by adding support for repeatable annotations of the same type.

Key changes:

• Deprecates AnnotationContainer#add and replaces it with AnnotationContainer#addSingle and AnnotationContainer#customizeSingle
  • AnnotationContainer#addSingle handles adding single annotations
  • AnnotationContainer#customizeSingle handles customizing single annotations
• Adds new AnnotationContainer#addRepeatable to support repeatable annotations
• Fixes KotlinSourceCodeWriter#writeProperty to correctly write annotations
• Refactors code to use the new methods instead of deprecated AnnotationContainer#add
• Adds tests

Fixes gh-1624

[mhalbritter]

Hello! The build is failing because of formatting violations. You can check them locally by running ./mvnw verify.

[YangSiJun528]

I made the fix and confirmed it works locally.

[mhalbritter]

Hello,

thanks for the PR! I might have missed something here, but why did you create a second implementation for the annotations? Is there a reason we couldn't add the functionality for repeated annotations into the AnnotationContainer itself?

[YangSiJun528]

After thinking more about your previous comment, I realized there might be a better approach that allows AnnotationContainer itself to support repeated annotations.
This way, it adds support for repeatable annotations without many code changes.

You can see it in this commit — I've confirmed that it doesn't break any existing tests:
YangSiJun528@488ce5a

Sorry if my earlier proposal ended up taking unnecessary time.

Do you think this approach would be better?
If you agree, I can update the PR with this version.

[mhalbritter]

Yes, please update the PR. Thanks!

[YangSiJun528]

I've updated the PR. @mhalbritter

[mhalbritter]

Thanks a lot @YangSiJun528 !