[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/media/manager_test.go

@@ -33,6 +33,7 @@ import (
 	"github.com/stretchr/testify/suite"
 	gtsmodel "github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/media"
+	"github.com/superseriousbusiness/gotosocial/internal/state"
 	gtsstorage "github.com/superseriousbusiness/gotosocial/internal/storage"
 )
 
@@ -1189,15 +1190,19 @@ func (suite *ManagerTestSuite) TestSimpleJpegProcessBlockingWithDiskStorage() {
 		panic(err)
 	}
 
+	var state state.State
+
+	state.Workers.Start()
+	defer state.Workers.Stop()
+
 	storage := &gtsstorage.Driver{
 		KVStore: kv.New(disk),
 		Storage: disk,
 	}
+	state.Storage = storage
+	state.DB = suite.db
 
-	diskManager, err := media.NewManager(suite.db, storage)
-	if err != nil {
-		panic(err)
-	}
+	diskManager := media.NewManager(&state)
 	suite.manager = diskManager
 
 	// process the media with no additional info provided