[GITEA] add new gitea service (release/languages) (#9781)

* add gitea service based on gitlab

* update gitea to use mocks

* add gitea release test

* move tests to use public repo on codeberg and fixes

* add pagination, update tests to live, set gitea_url as required

* add auth test (wip)

* fix base auth test

* fix required optionalUrl, remove default, assume semver from firstpage

* update example to use stable repository