fix hashCode and equals for AdditionalProperties and generateAliasAsM…

[jpfinne]

Fix compilation error for hashcode #20795

(replace #20831 that have merge issues)

Equals also uses additionalProperties if present.

The fixes are for java feign/resttemplate/jersey2/jersey3/native/okhttp-gson/webclient and JavaSpring

@NilsDammenhayn
The generated code still uses the "new" way of 7.12.0

private Map<String, Object> additionalProperties;

instead of

extends HashMap<String, Object>

This PR only fixes the compilation error for resttemplate, webclient and feign

Microprofile still uses the extends HashMap

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[martin-mfg]

What happened to the changes in modules/openapi-generator/src/main/resources/Java/pojo.mustache? It seems they got lost - or are they not needed?
Other than this the changes look good to me.

[jpfinne]

What happened to the changes in modules/openapi-generator/src/main/resources/Java/pojo.mustache? It seems they got lost - or are they not needed? Other than this the changes look good to me.

'{{>libraries/xxx/additional_properties}} are only defined in the pojo.mustache for the individual libraries.
So Map<String, {{{.}}}> additionalProperties is not generated by the default java/pojo. mustache

Thanks for the review

[jpfinne]

@martin-mfg @wing328 Is there anything that blocks the merge of this PR?

[martin-mfg]

@martin-mfg @wing328 Is there anything that blocks the merge of this PR?

Mainly the merge conflicts. Please resolve them when you have time. Other than this the PR looks good to me. So then we just need to wait for @wing328 to merge it.