Spring request mapping mode

[cachescrubber]

requestMappingMode: Explicit configuration to control the location of the generated class level RequestMapping annotation

Since #10573, the @ RequestMapping has been moved from the controller to the generated api interface.
This introduced incompatibilities in many scenarios, but specially when spring-cloud is used as a library. Unfortunately the fix from @MelleD (#13546) does not allow to override the default (for example when using interfaceOnly). This PR introduces a dedicated cli option to decide where the RequestMapping annotation should be placed.

`
requestMappingMode
Where to generate the class level @RequestMapping annotation. (Default: controller)
iface - Generate the @RequestMapping annotation on the generated Api Interface.
controller - Generate the @RequestMapping annotation on the generated Api Controller Implementation.
none - Do not add a class level @RequestMapping annotation.

`

The default is controller, which is the same as before #10573. By explicitly using iface, the annotation could be added to the api interface.

Caused By

• [Spring] Fix generated api ignore basePath #10573

Based on

• Remove wrong request mapping for feign clients #13546

Fixes

• [BUG] Java/Spring: @RequestMapping is unconditionally added to controller with property expression #13552
• [BUG] @RequestMapping annotation not allowed on @FeignClient interfaces #13488

PR checklist

• [x ] Read the contribution guidelines.
• [ x] Pull Request title clearly describes the work in the pull request and Pull Request description provides details about how to validate the work. Missing information here may result in delayed response from the community.
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  ./mvnw clean package 
  ./bin/generate-samples.sh
  ./bin/utils/export_docs_generators.sh
  

  Commit all changed files.
  This is important, as CI jobs will verify all generator outputs of your HEAD commit as it would merge with master.
  These must match the expectations made by your contribution.
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• File the PR against the correct branch: master (6.1.0) (minor release - breaking changes with fallbacks), 7.0.x (breaking changes without fallbacks)
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[cachescrubber]

Note to self. IIRC, we need to restore the. useFeignClientUrl functionality introduced in #12250

[cachescrubber]

@welshm (2022/02) @MelleD (2022/02) @atextor (2022/02) @manedev79 (2022/02) @javisst (2022/02) @borsch (2022/02) @banlevente (2022/02) @Zomzog (2022/09)

Please review

[welshm]

Minor comments about naming and defaults - but looks great thanks for fixing!