Geo: Display Custom Avatars in secondary nodes

This MR introduces some small patches for `User`, `Project` and `Group` models and related classes to build the avatar URL pointing to the primary node.
We should be able to remove this in the future when we start replicating local assets in Geo (#76).

For the changes to take effect on all pages, it's required to run:

```
# for Omnibus GitLab installs:
gitlab-rake cache:clear

# for Source installs:
RAILS_ENV=production bundle exec rake cache:clear
```

Closes #1128

See merge request !904

Merge branch '1291-documentation-about-lfs-objects-not-being-copied-when-mirroring-is-active' into 'master'

Add notes about LFS/Annex objects not being synced

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/1291

- [x] Change docs
- [x] Change views

See merge request !917

[ci skip]

Refactor issuable_filters_present to reduce duplications

Port of gitlab-org/gitlab-ce!7776

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/23546

See merge request !921

small but mighty confusing typo

See merge request !920

Fixing typo & Clarifying Key name

There was a small typo in this file and the key type was incorrect. Fixed both. 🎂

See merge request !923

Speed up Group security access specs

This is the Group equivalent of gitlab-org/gitlab-ce@13ad9a745a392e0bf0cedd0e1f318c1acee9b969

EE version of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7813

See merge request !924

Clarify where the settings are in Pages docs

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/1333

[ci skip]

See merge request !925

Fixes https://gitlab.com/gitlab-org/gitlab-ee/issues/1333

[ci skip]

This is the Group equivalent of 13ad9a74

Speed up Project security access specs

Prior, every single test was creating four `ProjectMember` objects, each
of which created one `User` record, even though each test only used
_one_ of those Users, if any.

Now each test only creates the single user record it needs, if it needs
one. This shaves minutes off of each spec file changed here.

EE version of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7779

See merge request !919

Prior, every single test was creating four `ProjectMember` objects, each
of which created one `User` record, even though each test only used
_one_ of those Users, if any.

Now each test only creates the single user record it needs, if it needs
one. This shaves minutes off of each spec file changed here.

CE upstream

See merge request !912

[ci skip]

[ci skip]

[ci skip]

[ci skip]

See https://gitlab.com/gitlab-org/gitlab-ce/issues/23546

See merge request !7776
Signed-off-by: Rémy Coutable <remy@rymai.me>

Port of rephrase-system-notes to EE

See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7692

See merge request !913

Fix StrongAttibutes error with Ruby 2.1

Similarly to gitlab-org/gitlab-ce!7625

See merge request !909

You can only assign default_branch when editing a project

Related to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7726

See merge request !7741

You can only assign default_branch when editing a project or when creating a project for a specified user [ci skip]

You can only assign default_branch when editing a project [ci skip]

changes environment.last_deployment to a try expression so it does not fail if e…

## What does this MR do?

Fixes the call on `environment.last_deployment` to not break when `environment`is not yet set.

## Does this MR meet the acceptance criteria?

- [x] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #24779

See merge request !7671

Don't convert data which already is the target type

With Grape's DSL we already enforce data types. We don't need to explicitly convert to string if there is already one.

See merge request !7740

Signed-off-by: Rémy Coutable <remy@rymai.me>

Move admin spam spinach test to RSpec

See merge request !7708

Merge branch '24908-install-instructions-seem-to-have-two-database-steps-out-of-order' into 'master'

Fix documentation to create the `pg_trm` extension before creating the DB

Closes #24908

See merge request !7735

Add missing documentation.

## What does this MR do?

Add documentation to Build events on webhooks

See merge request !7717