Logging: Log frontend errors (#28073)

* basic frontend  Sentry integration

* backend endpoint to capture sentry events

* WIP!

* log user email for frontend logs

* remove debug logging

* lint fixes

* Fix type exports & property names

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* additional struct naming fix

* rename log endpoint, config section & interface

* add sentry sample rate to config

* refac to use EchoSrv

* log user id

* backend tests

* tests for SentryEchoBackend

* sentry echo backend tests

* CustomEndpointTransport tests

* Update pkg/api/frontend_logging_test.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Update conf/defaults.ini

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* Update pkg/api/frontend_logging_test.go

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* don't export unnecesasrily

* update go.sum

* get rid of Convey in tests, use stdlib

* add sentry config to sample.ini

* cleanup to set orig logging handler in test

* Apply suggestions from code review

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

* PR feedback changes

* lock sentry version

Co-authored-by: Arve Knudsen <arve.knudsen@gmail.com>

pkg/api/api.go

@@ -445,4 +445,7 @@ func (hs *HTTPServer) registerRoutes() {
 	r.Get("/api/snapshots/:key", Wrap(GetDashboardSnapshot))
 	r.Get("/api/snapshots-delete/:deleteKey", reqSnapshotPublicModeOrSignedIn, Wrap(DeleteDashboardSnapshotByDeleteKey))
 	r.Delete("/api/snapshots/:key", reqEditorRole, Wrap(DeleteDashboardSnapshot))
+
+	// Frontend logs
+	r.Post("/log", bind(frontendSentryEvent{}), Wrap(hs.logFrontendMessage))
 }