Revert "Merge branch '44870-remove-extra-space-around-comment-form-on-merge-requests' into 'master'"

This reverts merge request !18120

Signed-off-by: NTakuya Noguchi <takninnovationresearch@gmail.com>

FE review changes - remove internal details assertion and look for closest form if no discussion_line_code

Added discussion_line_code value to note response and use it to query the right row for the discussion UI

Otherwise, when an error occurred, the content was escaped and
re-escaped on every error.

Fixes #37724

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/38871

changed how the container class is added onto the text element
more specs

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.

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

Fix Live Comment XSS Vulnerability

See merge request gitlab/gitlabhq!2183