Fixes #2740 : Add mockMaker option to @Spy annotation - #3835

Spy had no way to select a MockMaker per field, so the annotation-based spies always used the globally configured maker. Mock supports mockMaker since 4.8.0, so this PR closes that gap by implementing the same for Spy.

In addition to that, removing TODOs coming from the duplication of the spy-creation logic, extracted into SpyAnnotationUtil.

Example

@Spy(mockMaker = MockMakers.SUBCLASS) Foo spyOnFoo = new Foo("arg");

Fixes #2740

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