[#20718] [Java] fixed code generation for jersey2/3 and okhttp-gson when using modelMapping with a package and anyOf/oneOf

[xtroce]

issue-20718 fixed code generation for jersey2/3 and okhttp-gson when using modelMapping with a package and anyOf/oneOf

Added a method to get a sanitized dataType string
Added sanitation when the datatype is used in variable names in the Jersey2/Jersey3/OkHttp-Gson mustache files for anyOf and oneOf
Added 1 test that tests the sanitizing method itself
Added 3 tests for the combination anyOf & oneOf with jersey2, jersey3 and okhttp-gson

Since the fix has a problem with mappedSchema's I decided to add a separate file, since adding to the fake petstore would make it necessary to add a mapping to all tests that currently use it.

The sanitation consists of:

1. removing annotations (which was already done in most cases)
2. stripping all characters except alphanumeric ones from the dataType

The sanitize method is then used in the mustache files, when the dataType would be used as a variable name or in the name of a method.

The changes only impact the Java code generation:
@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)

Since it introduces a feature/but does not introduce a change in any behaviour, this commit is imho a minor version change.

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[wing328]

please resolve the merge conflicts when you've time

[xtroce]

@wing328 i merged master again and solved the conflict

[wing328]

just merged another java related pr

can you please resolve the merge conflicts one more time? will try to get this PR reviewed first tomorrow

thanks again for the contribution

[xtroce]

just merged master again : )