[Feat][Java] jaxrs-cxf-client support swagger v3

[peace317]

When generating Java 17 / jakarta compatible Code with the jaxrs-cxf-client generator the swagger2 annotations are a not compatible, because they contain javax imports. I added an optional flag to generate those oas3 Annotations. To maintain the mustache api files better, i created a new one and switch to it, when the flag is set.

fix #19907

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[wing328]

i did a test with

java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g jaxrs-cxf-client -i  https://raw.githubusercontent.com/OpenAPITools/openapi-generator/13a8a0a68eb1d3919648cee2930778f27c6887bc/modules/openapi-generator/src/test/resources/3_1/java/issue_19907.yaml -o /tmp/jaxrs2/ --additional-properties useJakartaEe=true,oas3=true

but the output won't compile, e.g.

[ERROR]   symbol:   class Schema
[ERROR]   location: class org.openapitools.model.Pet
[ERROR] /C:/Users/wing3/AppData/Local/Temp/jaxrs2/src/gen/java/org/openapitools/model/Pet.java:[49,4] cannot find symbol
[ERROR]   symbol:   class Schema
[ERROR]   location: class org.openapitools.model.Pet
[ERROR] /C:/Users/wing3/AppData/Local/Temp/jaxrs2/src/gen/java/org/openapitools/model/Tag.java:[16,4] cannot find symbol
[ERROR]   symbol:   class Schema
[ERROR]   location: class org.openapitools.model.Tag
[ERROR] /C:/Users/wing3/AppData/Local/Temp/jaxrs2/src/gen/java/org/openapitools/model/Tag.java:[19,4] cannot find symbol
[ERROR]   symbol:   class Schema
[ERROR]   location: class org.openapitools.model.Tag
[ERROR] -> [Help 1]

did you see similar issue locally when trying to compile the output?

[peace317]

This PR was implemented and merged with #22010. Fixed version is 7.16.0