Support passing custom annotations to generated code

還沒有人認領這個 Issue。

With the work in PR https://github.com/mapstruct/mapstruct/pull/2792 being done for https://github.com/mapstruct/mapstruct/issues/1574 it would be good to provide some support for the new API in the IntelliJ plugin as well.

Some things that we should do:

- [ ] Auto completion support for `AnnotateWith.Element#name` and error when `name` does not exist in target enum.
- [ ] Smart auto completion for `AnnotateWith.Element#classes` (pick the class type based on the one in the annotation
- [ ] Auto completion for `AnnotateWith.Element#enums` and error when enum value does not exist
- [ ] Annotation cannot annotated the generated class / method (it doesn't have the right target element type)
- [ ] Error when more than one value type is provided, eg. `shorts()` and `strings()`
- [ ] Error when duplicated `AnnotateWith.Element#name` (more than one having the same name
- [ ] Error when value does not match target annotation value type
- [ ] Error when using array value, but target value is not an array

先閱讀 PR #2792 和 issue #1574，以了解新的 AnnotateWith API，接著檢查 IntelliJ 外掛程式現有的產生註解支援。完成條件是實作並驗證列出的補全和錯誤檢查，包括目標相容性、重複名稱、值型別和陣列。

由索引模型根據 Issue 內容生成。