[ticket/13164] Update post_visibility before event is triggered

PHPBB3-13164
[ticket/13164] Add post_visibility to core.submit_post_end event

PHPBB3-13164
[ticket/13164] Fix syntax error

PHPBB3-13164
[ticket/12796] Add view own profile to UCP (and vice versa)

PHPBB3-12796
[ticket/12796] Use &amp; in path

PHPBB3-12796
[ticket/12796] Use dedicated lang vars

PHPBB3-12796
[ticket/13138] Do not use cookie data and autologin while forcing a user_id

PHPBB3-13138
Merge branch 'ticket/13138-2' into ticket/13138-asc

Conflicts:
	phpBB/phpbb/session.php
Merge remote-tracking branch 'PayBas/ticket/12796' into develop-ascraeus

* PayBas/ticket/12796:
  [ticket/12796] Use dedicated lang vars
  [ticket/12796] Use &amp; in path
  [ticket/12796] Add view own profile to UCP (and vice versa)
[ticket/12568] Replace modifications explanation with extensions.

PHPBB3-12568
[ticket/12568] Update path to language pack installation page.

PHPBB3-12568
[ticket/12568] Update style installation instructions.

PHPBB3-12568
[ticket/12568] Remove various unnecessary references to phpBB3.

PHPBB3-12568
[ticket/12568] Fix typo - "directorie" -> "directories"

PHPBB3-12568
[ticket/12568] Update GitHub link.

PHPBB3-12568
[ticket/12568] The "Purge cache" option in the Customise tab no longer exists.

PHPBB3-12568
[ticket/12568] Fix awkward use of "phpBB Limited."

PHPBB3-12568
[ticket/13138] Fix the session key tests

PHPBB3-13138
[ticket/13138] Type hint the variables for IDE usage

PHPBB3-13138
[ticket/13171] Check the correct (soft)delete permission when deleting in MCP

PHPBB3-13171