This reverts merge request !28545

This is a CSS effort only.

Fixes the padding of the buttons to be `8px 12px`
(including border) so that the button height is
32px.

Also adjusts the border width for all buttons when
the state is `hover`, `focus`, or `active to be 2px
thick instead of 1px thick. This is accomplished
through an inset box-shadow as not to increase
the size of the button.

Fixes some colors for primary and tertiary buttons.

On all the issue lists -- Group, Project and Dashboard -- this
change adds a new option for managing the lists.

"Manual Ordering" option is added which when flipped on will allow
an user to drag and drop issues around to create a relative ordering
among them.

Add changelog file

Added stylelint to static-analysis
Updated yarn dependencies
CSS Fixes and rule adoptions of stylelint
Added stylelint-scss
Deduplicated yarn.lock to clear dependencies

First round of advanced stylelint rules

Mainly Vendor prefix updates related to flex

Updates to more webkit specific vendor prefixes

Finished all vendor specific fixes

Moved now 4 rules to warning

Fixed the new scss lint problems

More stylelint adaptions after rebase

Updated the markup and styles for related merge requests in
issues page

Added button and modal to accept CSV file for uploading

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/40543
Bug introduced in
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15192

* new merge request can be created by sending an email to the specific
email address (similar to creating issues by email)
* for the first iteration, source branch must be specified in the mail
subject, other merge request parameters can not be set yet
* user should enable "Receive notifications about your own activity" in
user settings to receive a notification about created merge request

Part of #32878

Added by
https://gitlab.com/gitlab-org/gitlab-ee/commit/88aea2cbc8633ba970335d935d725bd17654b424

Part of this MR: https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1797/

Closes #31228