CloudMigrations: Fix bugs found during local testing (#91163)

* send dashboard commands instead of dashboards

* move status updates before goroutine to ensure frontend polls

* fix syncing issues between snapshot state and resources

* make sessionUid a requirement for modifying snapshots

* move the function I meant to move earlier

* remove accidental commit

* another accidental commit

* verify UpdateSnapshot is called with sessionUid

* revert

* pass in session uid everywhere

* forgot to save

* fix unit test

* fix typo

* tiny tweak

pkg/services/cloudmigration/model.go

@@ -145,6 +145,7 @@ type ListSnapshotsQuery struct {
 
 type UpdateSnapshotCmd struct {
 	UID       string
+	SessionID string
 	Status    SnapshotStatus
 	Resources []CloudMigrationResource
 }