CloudMigrations: Query Grafana Migration Status for status while the snapshot is in the cloud (#90314)

* implement querying gms for snapshot status

* add some documentation

* provide snapshot resources after snapshot is created

* add rate limiting to backend

* fix compilation error

* fix typo

* add unit tests

* finish merge

* lint

* swagger gen

* more testing

* remove duplicate test

* address a couple PR comments

* update switch statement to a map

* add timeouts to gms client through the http client

* remove extra whitespace

* put method back where it was so the PR is less confusing

* fix tests

* add todo

* fix final unit test

pkg/services/cloudmigration/cloudmigrationimpl/xorm_store_test.go

@@ -173,7 +173,7 @@ func Test_SnapshotManagement(t *testing.T) {
 		// create a snapshot
 		cmr := cloudmigration.CloudMigrationSnapshot{
 			SessionUID: sessionUid,
-			Status:     "initializing",
+			Status:     cloudmigration.SnapshotStatusCreating,
 		}
 
 		snapshotUid, err := s.CreateSnapshot(ctx, cmr)
@@ -183,7 +183,7 @@ func Test_SnapshotManagement(t *testing.T) {
 		//retrieve it from the db
 		snapshot, err := s.GetSnapshotByUID(ctx, snapshotUid, 0, 0)
 		require.NoError(t, err)
-		require.Equal(t, cloudmigration.SnapshotStatusInitializing, string(snapshot.Status))
+		require.Equal(t, cloudmigration.SnapshotStatusCreating, snapshot.Status)
 
 		// update its status
 		err = s.UpdateSnapshot(ctx, cloudmigration.UpdateSnapshotCmd{UID: snapshotUid, Status: cloudmigration.SnapshotStatusCreating})
@@ -192,7 +192,7 @@ func Test_SnapshotManagement(t *testing.T) {
 		//retrieve it again
 		snapshot, err = s.GetSnapshotByUID(ctx, snapshotUid, 0, 0)
 		require.NoError(t, err)
-		require.Equal(t, cloudmigration.SnapshotStatusCreating, string(snapshot.Status))
+		require.Equal(t, cloudmigration.SnapshotStatusCreating, snapshot.Status)
 
 		// lists snapshots and ensures it's in there
 		snapshots, err := s.GetSnapshotList(ctx, cloudmigration.ListSnapshotsQuery{SessionUID: sessionUid, Page: 1, Limit: 100})