Restructure go project (#2356)

* Move main to cmd
* Move api to internal
* Move logger and manager to internal
* Move shell hiding code to separate package
* Decouple job from desktop and utils
* Decouple session from config
* Move static into internal
* Decouple config from dlna
* Move desktop to internal
* Move dlna to internal
* Decouple remaining packages from config
* Move config into internal
* Move jsonschema and paths to models
* Make ffmpeg functions private
* Move file utility methods into fsutil package
* Move symwalk into fsutil
* Move single-use util functions into client package
* Move slice functions to separate packages
* Add env var to suppress windowsgui arg
* Move hash functions into separate package
* Move identify to internal
* Move autotag to internal
* Touch UI when generating backend

pkg/job/context.go

@@ -0,0 +1,22 @@
+package job
+
+import (
+	"context"
+	"time"
+)
+
+type valueOnlyContext struct {
+	context.Context
+}
+
+func (valueOnlyContext) Deadline() (deadline time.Time, ok bool) {
+	return
+}
+
+func (valueOnlyContext) Done() <-chan struct{} {
+	return nil
+}
+
+func (valueOnlyContext) Err() error {
+	return nil
+}