Adds the groundwork needed in order to persist multi-line suggestions,
while providing the parsing strategy which will be reused for the
**Preview** as well.

Adds outdated, lines_above and lines_below columns to
suggestions table.

outdated - boolean which represents whether the suggestion
is outdated or not. For instance, if any line changed after
you left the multi-line suggestion, even though the note
is not outdated, it helps tracking if the content has changed
in the latest file. We cache this information in a column given
it's not a cheap operation to do for every suggestion in the
request time.
lines_below, lines_above - persists the parsed arguments from
`suggestion:-10+3` syntax, where `10` would be lines_above and
3 lines_below. We need that to dynamically calculate which
lines we should monitor for outdating / persisting the correct
content in from_content column.

Revert "Merge branch 'remove-unused-css-from-mr-24724' into 'master'"

See merge request gitlab-org/gitlab-ce!26609

Add development documentation for gitaly feature flags

See merge request gitlab-org/gitlab-ce!25624

Add admin documentation for gitaly-ruby

See merge request gitlab-org/gitlab-ce!26605

Add multiple MR assignees migration and background table population

See merge request gitlab-org/gitlab-ce!26496

Bump Rugged to 0.28.1

See merge request gitlab-org/gitlab-ce!26595

Backport EE API parameters in lib/api

See merge request gitlab-org/gitlab-ce!26369

Fix display of emoji in GFM docs

See merge request gitlab-org/gitlab-ce!26527

Upgrade bootstrap_form Gem

Closes #49856

See merge request gitlab-org/gitlab-ce!26568

GitalyClient spec: Remove the diff between CE/EE

See merge request gitlab-org/gitlab-ce!26610

Docs: Add automatic redirects to last batch of moved files

See merge request gitlab-org/gitlab-ce!25904

Edit wiki notes

See merge request gitlab-org/gitlab-ce!26452

Untangle Markdown/Diffs/Notes CSS mess

See merge request gitlab-org/gitlab-ce!26493

Show statistics also when repository is disabled

Closes #59390

See merge request gitlab-org/gitlab-ce!26509

Remove .raw from JavaScript fixture file names

Closes #59201

See merge request gitlab-org/gitlab-ce!26545

Remove .raw from JavaScript fixture file names

Closes #59201

See merge request gitlab-org/gitlab-ce!26430

(cherry picked from commit 79a45f7f)

This reverts merge request !26134

Fix and improve Gitaly TLS documentation

See merge request gitlab-org/gitlab-ce!26488

Docs: Add IP range info

Closes #58257

See merge request gitlab-org/gitlab-ce!26447

Added no efs mention to repo storage path and AWS

See merge request gitlab-org/gitlab-ce!25610

Removes EE differences for issues.scss

Closes gitlab-ee#10655

See merge request gitlab-org/gitlab-ce!26583

Remove redundant "Type of issue" heading

See merge request gitlab-org/gitlab-ce!26023

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