docs(groupware): OpenAPI improvements

* refactor some pkg/jmap and groupware methods to make more sense from
   an API point-of-view

 * add path parameter documentation, but automate it by injecting their
   definition into the OpenAPI YAML tree that is extracted from the
   source code using go-swagger as it is too cumbersome, repetitive and
   error-prine to document them in the source code; wrote a TypeScript
   file apidoc-process.ts to do so

 * add generating an offline HTML file for the OpenAPI documentation
   using redocly, and injecting a favicon into the resulting HTML; wrote
   a TypeScript file apidoc-postprocess-html.ts to do so

pkg/jmap/jmap_api.go

@@ -31,5 +31,5 @@ const (
 	logDownloadUrl = "download-url"
 	logBlobId      = "blob-id"
 	logUploadUrl   = "download-url"
-	logSince       = "since"
+	logSinceState  = "since-state"
 )