Ultimate Member - Social Activity 2.3.6

* Added: Activity post argument for visibility in REST API
* Tweak: Template overwrite versioning
* Fixed: Posting new activity wall post on the user profile
* Fixed: PHP warnings
* Fixed: Embed links styles
* Fixed: Issue with lack of the nonces in the um_adm_action handler

* Added: `um_social_activity_allowed_image_types` hook for extending files that can be uploaded in social wall.
* Fixed: Sanitizing content for activity posts. Added iframe tag and onclick attribute. Embed content and hashtags are fixed.

* Templates required update:

- comment-reply.php
- comment.php
- edit-post.php
- new.php
- user-wall.php

* Fixed: Pattern for parsing hashtags
* Fixed: wp-admin current screen selected submenu
* Fixed: Hashtags count link redirects to a blank Posts page
* Fixed: Extension settings structure