New generator: WSDL

[adessoDpd]

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Description of the PR

This PR adds a WSDL generator (mentioned in #9430 ). The generated WSDL file can for example be used to create java code by using apache cxf etc. . Furthermore a xml file named jaxb-customization.xml is created, which can be used to make sure that enums can be correctly generated from the WSDL.

[wing328]

@adessoDpd thanks for the PR, which looks good to start with.

I'll file another PR to make some minor enhancements later.

[wing328]

Filed #9613 for improvemnets

@adessoDpd can you please PM me via Slack when you've time?

https://join.slack.com/t/openapi-generator/shared_invite/enQtNzAyNDMyOTU0OTE1LTY5ZDBiNDI5NzI5ZjQ1Y2E5OWVjMjZkYzY1ZGM2MWQ4YWFjMzcyNDY5MGI4NjQxNDBiMTlmZTc5NjY2ZTQ5MGM