Migration Improvements (#122)

Update swagger docs

Update docs

Let the wunderlist migrator use the registerRoutes function

Add migration status table

Add migration status

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/122

pkg/modules/migration/migrator.go

@@ -28,4 +28,7 @@ type Migrator interface {
 	// The use case for this are Oauth flows, where the server token should remain hidden and not
 	// known to the frontend.
 	AuthURL() string
+	// Name holds the name of the migration.
+	// This is used to show the name to users and to keep track of users who already migrated.
+	Name() string
 }