[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>

vendor/codeberg.org/gruf/go-bitutil/abs.go

@@ -0,0 +1,29 @@
+package bitutil
+
+// Abs8 returns the absolute value of i (calculated without branching).
+func Abs8(i int8) int8 {
+	const bits = 8
+	u := uint64(i >> (bits - 1))
+	return (i ^ int8(u)) + int8(u&1)
+}
+
+// Abs16 returns the absolute value of i (calculated without branching).
+func Abs16(i int16) int16 {
+	const bits = 16
+	u := uint64(i >> (bits - 1))
+	return (i ^ int16(u)) + int16(u&1)
+}
+
+// Abs32 returns the absolute value of i (calculated without branching).
+func Abs32(i int32) int32 {
+	const bits = 32
+	u := uint64(i >> (bits - 1))
+	return (i ^ int32(u)) + int32(u&1)
+}
+
+// Abs64 returns the absolute value of i (calculated without branching).
+func Abs64(i int64) int64 {
+	const bits = 64
+	u := uint64(i >> (bits - 1))
+	return (i ^ int64(u)) + int64(u&1)
+}