* add API endpoint to create OAuth2 Application.
* move endpoint to /user. Add swagger documentations and proper response type.
* change json tags to snake_case. add CreateOAuth2ApplicationOptions to swagger docs.
* change response status to Created (201)
* add methods to list OAuth2 apps and delete an existing OAuth2 app by ID.
* add APIFormat convert method and file header
* fixed header
* hide secret on oauth2 application list
* add Created time to API response
* add API integration tests for create/list/delete OAuth2 applications.
Co-authored-by: techknowlogick <matti@mdranta.net>
Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>
