More apps menu not position in the right place

[rullzer]

@juliushaertl @skjnldsv

[nextcloud-bot]

GitMate.io thinks possibly related issues are #9715 (More apps menu wrong location), #2544 (Popover menu is in the wrong place in some apps), #7250 (Wrong position of the contacts menu for comment authors), #4016 (New apps menu, visual glitches), and #6390 (user_ldap: when removing a group from the right side it is placed at the bottom of the list instead of it's original position).

[weeman1337]

I'll have a look..

[raimund-schluessler]

I still see this issue on screensizes <480px due to https://github.com/nextcloud/server/blob/master/core/css/mobile.scss#L135-L142.

Happens on latest master.

[skjnldsv]

#10851