Handling special characters in Issuable Templates

Closes #40028

See merge request gitlab-org/gitlab-ce!15323

Update secret_values to support dynamic elements within parent

See merge request gitlab-org/gitlab-ce!16665

Fix .batch_lfs_pointers accepting a lazy enumerator

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

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

Default to HTTPS for all Gravatar URLs

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

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

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