* move Setting function into its own package
* swagger add&use new section "settings"
* move api AllowedReactions into general UI-Settings endpoint
* prepare TEST
* lint
Swagger needs a comment line above each swagger:response comment -- it
uses these to populate the description: fields. Adding minimal text
for now on the way to getting swagger validate to pass. Many standard
swagger client libraries will not work at all with gitea until validate
passes, so prioritizing that over better descriptions for now.
Signed-off-by: Steve Traugott <stevegt@t7a.org>