[performance] processing media and scheduled jobs improvements (#1482)

* replace media workers with just runners.WorkerPool, move to state structure, use go-sched for global task scheduling

* improved code comment

* fix worker tryUntil function, update go-runners/go-sched

* make preprocess functions package public, use these where possible to stop doubled up processing

* remove separate emoji worker pool

* limit calls to time.Now() during media preprocessing

* use Processor{} to manage singular runtime of processing media

* ensure workers get started when media manager is used

* improved error setting in processing media, fix media test

* port changes from processingmedia to processing emoji

* finish code commenting

* finish code commenting and comment-out client API + federator worker pools until concurrency worker pools replaced

* linterrrrrrrrrrrrrrrr

---------

Signed-off-by: kim <grufwub@gmail.com>

internal/router/router.go

@@ -117,7 +117,7 @@ func (r *router) Start() {
 	// "debug" or "debugenv" build-tag is set pprof stats will be served
 	// at the standard "/debug/pprof" URL.
 	r.srv.Handler = debug.WithPprof(r.srv.Handler)
-	if debug.DEBUG() {
+	if debug.DEBUG {
 		// Profiling requires timeouts longer than 30s, so reset these.
 		log.Warn("resetting http.Server{} timeout to support profiling")
 		r.srv.ReadTimeout = 0