Polylang Pro 3.6.1

* Add de_AT and pt_AO to the predefined languages list
* Pro: Add filter pll_translate_blocks
* Pro: fix PHP notice when the queried post type has been modified to an array
* Pro: fix PHP warning when combined with The Event Calendar and Page builder by SiteOrigin

* Pro: Fix translated slugs not accepting forward slashes
* Pro: Fix fatal error with ACF Pro 5.7.11
* Fix parent categories incorrectly synchronized #327

* Security: Fix categories and media duplication not protected from CSRF
* Pro: Allow to update the plugin with WP CLI
* Pro: Fix search in the button block not filtered in the correct language (needs WP 5.1)
* Add Saraiki to the predefined languages list
* Fix a conflict causing a blank page with Divi