yandex: complete rewrite

Get rid of the api client and use rest/pacer for all API calls
Add Copy, Move, DirMove, PublicLink, About optional interfaces
Improve general error handling
Remove ListR for now due to inconsitent behaviour
fixes #2586, progress on #2740 and #2178
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f