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/plugin_api.go

@@ -144,7 +144,11 @@ func (api *PluginAPI) GetSystemInstallDate() (int64, *model.AppError) {
 }
 
 func (api *PluginAPI) GetDiagnosticId() string {
-	return api.app.DiagnosticId()
+	return api.app.TelemetryId()
+}
+
+func (api *PluginAPI) GetTelemetryId() string {
+	return api.app.TelemetryId()
 }
 
 func (api *PluginAPI) CreateTeam(team *model.Team) (*model.Team, *model.AppError) {