#23915 [java][restclient][webclient] add localVar prefix to queryParams variables

add localVar prefix to avoid compilation errors due to name collisions.

another workaround is to use parameterNameMapping option: https://github.com/OpenAPITools/openapi-generator/blob/master/docs/customization.md#name-mapping

cc @bbdouglas (2017/07) @sreeshas (2017/08) @jfiala (2017/08) @lukoyanov (2017/09) @cbornet (2017/09) @jeff9finger (2018/01) @karismann (2019/03) @Zomzog (2019/04) @lwlee2608 (2019/10) @martin-mfg (2023/08)

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Summary by cubic

Adds the localVar prefix to the query param map in the Java restclient and webclient generators to prevent name collisions and align with existing naming. Regenerates samples and updates tests; no runtime changes.

• Refactors
  • Renamed queryParams to localVarQueryParams in Java/libraries/restclient/api.mustache and Java/libraries/webclient/api.mustache.
  • Regenerated Java restclient and webclient samples.
  • Updated JavaClientCodegenTest assertions to expect localVarQueryParams in both JSON and non-JSON query serialization.