Uses Lfs::FileModificationHandler to coordinate LFS detection, creation of LfsObject, etc

Caveats:
 1. This isn't used by the multi-file editor / Web IDE
 2. This isn't used on rename. We'd need to be able to download LFS files
    and add them to the commit if they no longer match so not as simple.
 3. We only check the root .gitattributes file, so this should be improved
    to correctly check for nested .gitattributes files in subfolders.

Open links in a new tab on the user page

See merge request gitlab-org/gitlab-ce!16705

Fix .batch_lfs_pointers accepting a lazy enumerator

See merge request gitlab-org/gitlab-ce!16701

Make Gitaly RepositoryExists opt-out

See merge request gitlab-org/gitlab-ce!16680

Look at system notes created just before merge as well as after, when deciding if an MR can be reverted

Closes #42377

See merge request gitlab-org/gitlab-ce!16678

Add note within ux documentation that further changes should be made within the…

See merge request gitlab-org/gitlab-ce!16686

Default to HTTPS for all Gravatar URLs

See merge request gitlab-org/gitlab-ce!16666

Generate ssh key on the fly for QA

See merge request gitlab-org/gitlab-ce!16562

Moves status icon into a vue file and adds tests

See merge request gitlab-org/gitlab-ce!16703

Add modal for deleting a milestone

Closes #41314

See merge request gitlab-org/gitlab-ce!16229

Revert "Merge branch 'osw-updates-merge-status-on-api-actions' into 'master'"

See merge request gitlab-org/gitlab-ce!16707

On MySQL, at least, `Note#created_at` doesn't seem to store fractional seconds,
while `MergeRequest::Metrics#merged_at` does. This breaks the optimization
assumption that we only need to search for notes created *after* the MR has
been merged.

Unsynchronized system clocks also make this a dangerous assumption to make.

Adding a minute of leeway still optimizes away most notes, but allows both
cases to be handled more gracefully. If the system clocks are more than a
minute out, we'll still be broken, of course.

Revert "Merge branch 'remove-rugged-walk' into 'master'"

See merge request gitlab-org/gitlab-ce!16676

This reverts merge request !16626

Can parse root .gitattributes file for a ref

See merge request gitlab-org/gitlab-ce!16418

Resolve "generalise not found status icon color throughout application"

Closes #42285

See merge request gitlab-org/gitlab-ce!16679

Resolve "Add empty state for pending job"

Closes #42220

See merge request gitlab-org/gitlab-ce!16646

* master: (30 commits)
  Resolve "Link to Clusters in Auto DevOps instead of Kubernetes service"
  Update CHANGELOG.md for 10.4.1
  Add a gRPC health check to ensure Gitaly is up
  Add formatted_data attribute to Git::WikiPage
  Avoid array indices to fixtures in JS specs
  Migrate .batch_lfs_pointers to Gitaly
  Updates `Revert this merge request` text
  Work around a bug in DatabaseCleaner when using the deletion strategy on MySQL
  Use the DatabaseCleaner 'deletion' strategy instead of 'truncation'
  Workaround a recaptcha pop-up that cannot be tested
  Moves more mr widget components into vue files Adds i18n Adds better test coverage
  Execute system hooks after-commit when executing project hooks
  Remove one Spinach job and add one RSpec job
  Migrate repository bundling to Gitaly
  Use limit for search count queries
  Fix offense in runners settings QA page object class
  Wait for runner until it registers itself in QA tests
  Fix static-analysis offenses in QA support class
  Add specific views / selectors for QA runners page
  Add views / selectors for pipeline show page object
  ...

This reverts merge request !16525

CI/CD end-to-end tests

Closes gitlab-qa#18

See merge request gitlab-org/gitlab-ce!16619

Link Auto DevOps settings to Clusters page

Closes #42053

See merge request gitlab-org/gitlab-ce!16641

Merge branch '42161-gitaly-commitservice-encoding-undefinedconversionerror-u-c124-from-utf-8-to-ascii-8bit' into 'master'

Resolve "Gitaly::CommitService: Encoding::UndefinedConversionError: U+C124 from UTF-8 to ASCII-8BIT"

Closes #42161

See merge request gitlab-org/gitlab-ce!16637

If using gravatar.com, both plain_url and ssl_url in settings are now
served via HTTPS. Make this the default.

Moves more mr widget components into vue files

See merge request gitlab-org/gitlab-ce!16677

Add a gRPC health check to ensure Gitaly is up

See merge request gitlab-org/gitlab-ce!16606

[ci skip]

This will enable Geo to skip shards that not operational.

Relates to gitlab-org/gitlab-ee#4329

Resolve ""Revert this merge request" modal has confusing string"

Closes #39917

See merge request gitlab-org/gitlab-ce!16611

Add note within ux documentation that further changes should be made within the design.gitlab project

Add formatted_data attribute to Git::WikiPage

Closes #39805

See merge request gitlab-org/gitlab-ce!16682

Use limit for search count queries

See merge request gitlab-org/gitlab-ce!16502

Related to #39805

Use the DatabaseCleaner 'deletion' strategy instead of 'truncation'

Closes #30783

See merge request gitlab-org/gitlab-ce!16516

Migrate .batch_lfs_pointers to Gitaly

Closes gitaly#921

See merge request gitlab-org/gitlab-ce!16517