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/session/config.go

@@ -0,0 +1,17 @@
+package session
+
+type ExternalAccessConfig interface {
+	HasCredentials() bool
+	GetDangerousAllowPublicWithoutAuth() bool
+	GetSecurityTripwireAccessedFromPublicInternet() string
+	IsNewSystem() bool
+}
+
+type SessionConfig interface {
+	GetUsername() string
+	GetAPIKey() string
+
+	GetSessionStoreKey() []byte
+	GetMaxSessionAge() int
+	ValidateCredentials(username string, password string) bool
+}