Add new language and prompt identifiers to custom text enums

[kushalshit27]

Changes

Add new language and prompt identifiers to custom text enums

Path	HTTP Method	Method Name
/prompts/{prompt}/custom-text/{language}	PUT	updateCustomTextByLanguage
/prompts/{prompt}/custom-text/{language}	GET	getCustomTextByLanguage

References

• original PR: feature/formsCustomText #1082
• ESD-45023

Testing

Please describe how this can be tested by reviewers. Be specific about anything not tested and reasons why. If this library has unit and/or integration testing, tests should be added for new functionality and existing tests should complete without errors.

• This change adds unit test coverage
• This change adds integration test coverage

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors