Reduced the technical debt around our JS flash function by making it a
module that is imported rather than relying on the global function.
The global function still exists mainly for technical debt with how
some requests are being completed, but new JS should import the module
directly.

Also reduces some tech debt in the file by removing the need for jQuery.
Instead Flash is now 100% vanilla JS.

Previously the fork button was disabled for all users if they have
exceeded their project limit. This fixes that by changing the check
to see if the user can fork to a group instead of their own namespace.

This behaviour is already possible by visiting the new fork page
directly, so this just fixes the button being disabled.

Closes #38462

Closes #38276

Nobody tell @jschatz1 :P

Removes set favicon related methods from global scope
Improves test related with favicon

Removes convertPermissionToBoolean from global scope.
Adds tests for convertPermissionToBoolean - were non existant

Removes setParamInURL from gl.utils

Removes parseIntPagination from gl.utils namespace

Remove normalizeCRLFHeaders from gl.utils namespace

Removes normalizeHeaders from gl.utils namespace

Use gl.utils for filtered search

Fix bad import

Fix broken test by cleaning window.history namespace

Adds changelog

the position of the popover is correctly calculated and positioned to
the bottom when the navigation would overlap the popover.

[ci skip]

The dispatcher was trying to create a new instance of a class that is loaded in a file after main.js which would cause the filtered search to not work on issues. This would only happen on the first load when the JS is not cached. If the JS is cached, then everything will be fine.

Closes #36207

According to https://github.com/twbs/bootstrap/issues/10547 it's not
possible to have the trigger defined on the delegated element, i.e. not
defined as a data attribute.

fixed duplication of code

correctly position the arrow
fix scss lint

Closes #34026

[ci skip]