Remove the assigned-user and label filters

Workflows now move every overdue card of their source stack. A new
migration drops filter_user_ids and filter_label_ids; workflows that
had a filter keep running unfiltered. The version goes to 35.1.0 so
the migration runs on update.

Removed along with the filters: the labels and participants endpoints
and their Deck lookups, the dead-filter warnings and markers, and
CardService::enrichCards() in the card read. enrichCards() only added
labels, assignees and comment counts, and ran a permission check
against Deck's frozen uid.

appinfo/routes.php

@@ -11,7 +11,5 @@ return [
 
 		['name' => 'workflow#boards', 'url' => '/api/v1/boards', 'verb' => 'GET'],
 		['name' => 'workflow#stacks', 'url' => '/api/v1/boards/{boardId}/stacks', 'verb' => 'GET'],
-		['name' => 'workflow#labels', 'url' => '/api/v1/boards/{boardId}/labels', 'verb' => 'GET'],
-		['name' => 'workflow#participants', 'url' => '/api/v1/boards/{boardId}/participants', 'verb' => 'GET'],
 	],
 ];