This changes the positioning of the image diff comments
from absolute x & y positions to instead use percents.
These percents then mean that the comment bubble can
correctly adjust depending on the screen size.

Closes https://gitlab.com/gitlab-org/gitlab/-/issues/225961

Of course, this means that there's a bunch of logic
to coordinate the new flag with the original -
`automaticallyCollapsed` - flag.

In addition: the UI is updated to use the new flag
whenever it's been set, but to continue to fall back
to the old flag. This is primarily facilitated by a new
helper utility for diff files to do the resolution in a
single centralized place.

Of note: the diff_file is updated to depend on the
global store as the authoritative source of determining
whether the file is collapsed or not. The previous
version kept a local `isCollapsed` in sync with the
global store, which introduced a huge amount of
interwoven complexity. The update ingests the
resolved collapsed state from the store when
various observed properties update instead of
inverting that flow.

This is a full refactor of file collapsing.
Because the previous version was a single flag, then
modified with a user preference (file-by-file), there
were some issues including a THIRD possible way
that collapsing works. This update slightly simplifies
how collapsing works by depending more heavily
on the two flags stored in state and only modifying
them with the user preference when necessary.

- This leaves a small inaccuracy since now the "manual" (user) collapsed
    files are toggling the "automatic" flag. This will be resolved in an
    upcoming merge request.

Will be replaced with GlSkeletonLoader, but for not this just
indicates that GlSkeletonLoading is deprecated

This enables an eslint rule to prevent
usage of v-html to avoid potential
XSS vulnerabilities

Also updates other components that eventually
use the same component

Error is just a boolean and should never be displayed.

We are migrating all specs in javascripts/notes to frontend/notes

The eslint rule paths have changed.
So we need to explitly change to the shorter path

only for CE-specific contents under /app/assets/javascripts/[j-n]*

Disables the vue-i18n eslint rules for files
that are not able to be autofixed, this will
stop these offences causing pipeline failures
but they will need manual fixing.

Disables the vue-i18n eslint rules for files
that are not able to be autofixed, this will
stop these offences causing pipeline failures
but they will need manual fixing.

i18n linting for .vue files under the
app/assets/javascripts/notes directory

i18n linting for .vue files under the
app/assets/javascripts/notes directory

Add test for checking output

We need this to be able to distinguish between Markdown tables and diff
tables.

We need this to be able to distinguish between Markdown tables and diff
tables.

- replaced file.too_large
- replaced file.text
- replaced file.collapsed

Before, diff file `higlighted_diff_lines`/`parallel_diff_lines` and
diff discussion `truncated_diff_lines` were inconsistent: `text` and
`rich_text` on the latter included the leading +/-/<space> character,
like on the backend, while the former had no `text` and its `rich_text`
had dropped this char.

This resulted in a bug when the suggestions feature expected these diff
line objects to be identical in format and thus interchangeable, which
was not the case.

Improve the renderign of new and existing discussions
by reducing the number of watchers on each object & array.
Previously every discussion change would trigger an update for every
discussion component.

Also tidied up some components to get them closer to our docs.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51506

This caused many pain points when working with it.
Part of the data was camel cased the other snake case.
Other parts where snake case & then getting converted in components,
this conversion has the potential for leaking memory.

This changes that & makes it consistent with what it returned from the
API, snake case.

This re-implements image commenting in merge request diffs.
This feature was previously lost when the merge request
page was refactored into Vue.

With this, we create an overlay component. The overlay
component handles displaying the comment badges
and the comment form badge.
Badges are displayed based on the position attribute
sent with the discussion.

Comment forms for diff files are controlled through
a different state property. This is so we don't
tie comment forms to diff files directly creating
deep nested state. Instead we create a flat array
which holds the file hash & the X & Y position of
the comment form.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/48956