Add option to disable contactsmenu badge in top right header

Is your feature request related to a problem? Please describe.

Hello ! By default there are 3 ways to search for contacts : through the contact app page, through unified search, then again through a badge in the header named "contactsmenu".

Describe the solution you'd like

Set a config variable to disable the contactsmenu badge in the header.

Example :
php occ config:app:set contacts header_badge --type=boolean --value=false

Describe alternatives you've considered

Css that only hides it but could be enabled again through the browser.
#contactsmenu{display:none}

Or manually removing the div in corresponding php files but not sustainable through upgrades.

Locate the code that renders the header's contactsmenu badge and inspect how this app currently reads configuration values. Add the header_badge setting described in the issue, then verify that php occ config:app:set contacts header_badge --type=boolean --value=false disables the badge without affecting the other contact search paths.