feat: add cross-origin reporting for telemetry in the dashboard (#13612)

* feat: add cross-origin reporting for telemetry in the dashboard

* Respect the telemetry flag

* Fix embedded metadata

* Fix compilation error

* Fix linting

coderd/telemetry/telemetry.go

@@ -93,6 +93,7 @@ type Reporter interface {
 	// database. For example, if a new user is added, a snapshot can
 	// contain just that user entry.
 	Report(snapshot *Snapshot)
+	Enabled() bool
 	Close()
 }
 
@@ -109,6 +110,10 @@ type remoteReporter struct {
 	shutdownAt *time.Time
 }
 
+func (*remoteReporter) Enabled() bool {
+	return true
+}
+
 func (r *remoteReporter) Report(snapshot *Snapshot) {
 	go r.reportSync(snapshot)
 }
@@ -948,4 +953,5 @@ type ExternalProvisioner struct {
 type noopReporter struct{}
 
 func (*noopReporter) Report(_ *Snapshot) {}
+func (*noopReporter) Enabled() bool      { return false }
 func (*noopReporter) Close()             {}