Moving diagnostics into a service (#14832)

* Moving diagnostics into a service

* Fixing golint checks

* Fixing tests

* Renaming from diagnostics to telemetry

* Adding missing files

* Initializing telemetry earlier in the server startup

* Fixing tests

* Adding a log for the telemetryID initialization error

* Addressing PR review comments

* Fixing merge problem

* Removing some extra Diagnostics mentions

* Making tests pass

app/permissions.go

@@ -54,7 +54,7 @@ func (a *App) ResetPermissionsSystem() *model.AppError {
 	}
 
 	// Remove the "System" table entry that marks the advanced permissions migration as done.
-	if _, err := a.Srv().Store.System().PermanentDeleteByName(ADVANCED_PERMISSIONS_MIGRATION_KEY); err != nil {
+	if _, err := a.Srv().Store.System().PermanentDeleteByName(model.ADVANCED_PERMISSIONS_MIGRATION_KEY); err != nil {
 		return model.NewAppError("ResetPermissionSystem", "app.system.permanent_delete_by_name.app_error", nil, err.Error(), http.StatusInternalServerError)
 	}