Bug fixes

Update for latest PHPStan Drupal release to keep up with upstream fixes. #3189376: Upgrade Status should no longer declare a conflict with phpstan/phpstan:^0.12.43

Issue #3188489 by jurgenhaas: Recognize digsig content setting changes for schedule update
Fix missing javascript dependency

Drupal 9 Compatibility

• Fix issue 3059771: Hook Help is missing
• Fix issue 3141447: Automated Drupal Rector fixes
• Replace API URLs to reach the new URLs without being redirected
• Replace deprecated shards by the new ones
• Remove deprecated function getMatches()

Fix some incompatibility with Queue UI module. Improved Scheduler API integration.

Updates

* Many code review-related fixes (code style, dependency injection etc).
* This also fixes a serious issue with the "relationship type" field on a task edit form being mistaken for the task's type (i.e. bundle), leading to plugin issues. There is an update hook to fix any data that was broken by this.