Added user language setting (#3875)

* Added user language setting

* Added translation string for setting

* Fixed import order + typo

* improved checking if the user has a language saved in the db

* The current saved language is now set a default inside the dropdown

* fmt

* When a user signs in and doesn't have a language saved, the current browser language is saved

* updated gitea-sdk

* Merge branch 'master' of https://github.com/go-gitea/gitea into save-user-language

# Conflicts:
#	models/migrations/migrations.go
#	models/migrations/v62.go

* Made tests work again

* trigger CI

* trigger CI

* fmt

* re-trigger that FUCKING CI SO IT REALLY PICKS UP THE LATEST COMMIT ISTEAD OF PREDENDING TO DO SO

* re-trigger that FUCKING CI SO IT REALLY PICKS UP THE LATEST COMMIT ISTEAD OF PREDENDING TO DO SO

* When loggin in, only the language col gets updated instead of everything

public/swagger.v1.json

@@ -7318,6 +7318,11 @@
           "format": "int64",
           "x-go-name": "ID"
         },
+        "language": {
+          "description": "User locale",
+          "type": "string",
+          "x-go-name": "Language"
+        },
         "login": {
           "description": "the user's username",
           "type": "string",