Deprecate $gl-gray- variables and replace with $gray- variables
to syncronize the use of gray variables.

Changed $gray-200 hex and started replacing instances of $gray-200
with $gray-100.

refactors the ui for diverging commits so that it's only a single
bar instead of two separate bars

Remove jquery.scss; Combine multiple duplicate grays into global gray variables; Remove unused styles in common.scss

Remove jquery.scss; Combine multiple duplicate grays into global gray variables; Remove unused styles in common.scss

These are not present in CE and seem to have originated from a merge
commit back in January. Since the selectors aren't used anywhere we can
just safely remove these files.

Improve the consistency of commit titles, branch names, tag names, issue/MR titles, on their respective project pages