We had concerns about the cached values on Redis with the previous two
releases strategy:

First release (this commit):
  - Create new encrypted fields in the database.
  - Start populating new encrypted fields, read the encrypted fields or
    fallback to the plaintext fields.
  - Backfill the data removing the plaintext fields to the encrypted
    fields.
Second release:
  - Remove the virtual attribute (created in step 2).
  - Drop plaintext columns from the database (empty columns after
    step 3).

We end up with a better strategy only using migration scripts in one
release:
  - Pre-deployment migration: Add columns required for storing encrypted
    values.
  - Pre-deployment migration: Store the encrypted values in the new
    columns.
  - Post-deployment migration: Remove the old unencrypted columns

Some feature allows GUEST to access only if project is not private.
This method returns access level when targeting private projects.

Guest are blocked to certain feature when project is private,
therefore the scope would filter additionally with REPORTER level.

This is the plan to encrypt the plaintext tokens:

First release (this commit):
  1. Create new encrypted fields in the database.
  2. Start populating new encrypted fields, read the encrypted fields or
     fallback to the plaintext fields.
  3. Backfill the data removing the plaintext fields to the encrypted fields.

Second release:
  4. Remove the virtual attribute (created in step 2).
  5. Drop plaintext columns from the database (empty columns after step 3).

Notes related to branch creation should not be shown in an issue's
activity feed when the user doesn't have access to :download_code.

- Include new types in SystemNoteMetadata
- Add Label and Milestone reference_pattern to
Mentionable::ReferenceRegexes to be checked for cross references

This will be used later for search filtering.

This is to be more consistent as there is already a :read_note policy in
NotePolicy. To keep other behaviour the same we've introduced a
Note#noteable_ability_name that is used anywhere this was expected.

Previously, when the wiki page format was anything other than `markdown`
or `asciidoc` the formatted content would be returned though a Gitaly
call. Gitaly in turn would delegate formatting to the gitlab-gollum-lib
gem, which in turn would delegate that to various gems (like RDoc for
`rdoc`) and then apply some very liberal sanitization.

It was too liberal!

This change brings our wiki content formatting in line with how we
format other markdown at GitLab, so we have a SSOT for sanitization.

https://gitlab.com/gitlab-org/gitlab/issues/30540

Use project scopes to filter project labels that are visible for user

Quarantine some ECDSA related tests due to bumping openssl

See merge request gitlab-org/gitlab!18016

Add spec to test different combinations.
Accept string for required_minimum_access_level
Allow more flexible project membership query

This prevents a MITM attack where attacker could
still access Git repository if any jobs were
running long enough.