Rename column in the database
 Rename fields related to import/export feature
 Rename API endpoints
 Rename documentation links
 Rename the rest of occurrences in the code
 Replace the images that contain the words "build succeeds" and docs referencing to them
 Make sure pipeline is green and nothing is missing.

updated doc images

renamed only_allow_merge_if_build_succeeds in projects and fixed references

more updates

fix some spec failures

fix rubocop offences

fix v3 api spec

fix MR  specs

fixed issues with partials

fix MR spec

fix alignment

add missing v3 to v4 doc

wip - refactor v3 endpoints

fix specs

fix a few typos

fix project specs

copy entities fully to V3

fix  entity error

more fixes

fix failing specs

fixed missing entities in V3 API

remove comment

updated code based on feedback

typo

fix spec

The default (false) is not strictly required, and this lets us avoid a
potentially expensive migration

Rather than using a separate `ghost` state. This lets us have the benefits of
both ghost and blocked users (ghost: true, state: blocked) without having to
rewrite a number of queries to include cases for `state: ghost`.

and remove the old one which we don't really need.

https://gitlab.com/gitlab-org/gitlab-ce/issues/27762#note_23520780

This reverts commit f2ed7cbc9b36b6ad9bcc714b271e98ead756b816.

https://gitlab.com/gitlab-org/gitlab-ce/pipelines.json makes
a number of unindexed slow queries. This index should
speed things up.

Signed-off-by: NDmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

We can't properly use foreign keys on columns that are configured for
polymorphic associations which has disadvantages related to data
integrity and storage. Given we only use time tracking for Issues and
Merge Requests we're moving to the usage of regular associations.

Store the value in application settings.
Expose the value to Workhorse.

When loading pages that display the number of open issues,
the backend runs a query such as:

```sql
SELECT "labels"."id" FROM "labels" WHERE "labels"."type" IN ('ProjectLabel') AND "labels"."project_id" = 1000
```

This results in an entire scan of the `labels` table. To optimize performance,
add the appropriate index to the table.

Closes #27676

Changed how components are added in objects

- The pages are created when build artifacts for `pages` job are uploaded
- Pages serve the content under: http://group.pages.domain.com/project
- Pages can be used to serve the group page, special project named as host: group.pages.domain.com
- User can provide own 403 and 404 error pages by creating 403.html and 404.html in group page project
- Pages can be explicitly removed from the project by clicking Remove Pages in Project Settings
- The size of pages is limited by Application Setting: max pages size, which limits the maximum size of unpacked archive (default: 100MB)
- The public/ is extracted from artifacts and content is served as static pages
- Pages asynchronous worker use `dd` to limit the unpacked tar size
- Pages needs to be explicitly enabled and domain needs to be specified in gitlab.yml
- Pages are part of backups
- Pages notify the deployment status using Commit Status API
- Pages use a new sidekiq queue: pages
- Pages use a separate nginx config which needs to be explicitly added

As described in #27443, the `project_authorizations` table is often used to retrieve
all team members of this project. This can lead to a number of slow queries impacting
load times. This MR adds an index for just `project_id`.

Closes #27443

* Instead of using the proposed `coverage` key, this expects `coverage_regex`

This MR enables rendering of PlantUML diagrams in Asciidoc documents. To add a
PlantUML diagram all we need is to include a plantuml block like:

```
[plantuml, id="myDiagram", width="100px", height="100px"]
--
bob -> alice : ping
alice -> bob : pong
--
```

The plantuml block is substituted by an HTML img element with *src* pointing to
an external PlantUML server.

This MR also add a PlantUML integration section to the Administrator -> Settings
page to configure the PlantUML rendering service and to enable/disable it.

Closes: #17603

Addresses: Issue #13810

1. Adds a last_used_at attribute to the Key table/model
2. Update a key's last_used_at whenever it gets used
3. Display how long ago an ssh key was last used

This column used to be a 32 bits integer, allowing for only a maximum of
2 147 483 647 rows. Given enough users one can hit this limit pretty
quickly, as was the case for GitLab.com.

Changing this type to bigint (= 64 bits) would give us more space, but
we'd eventually hit the same limit given enough users and projects. A
much more sustainable solution is to simply drop the "id" column.

There were only 2 lines of code depending on this column being present,
and neither truly required it to be present. Instead the code now uses
the "project_id" column combined with the "user_id" column. This means
that instead of something like this:

    DELETE FROM project_authorizations
    WHERE user_id = X
    AND id = Y;

We now run the following when removing rows:

    DELETE FROM project_authorizations
    WHERE user_id = X
    AND project_id = Y;

Since both user_id and project_id are indexed this should not slow down
the DELETE query.

This commit also removes the "dependent: destroy" clause from the
"project_authorizations" relation in the User and Project models.
Keeping this prevents Rails from being able to remove data as it relies
on an "id" column being present. Since the "project_authorizations"
table has proper foreign keys set up (with cascading removals) we don't
need to depend on any Rails logic.

Revert MattermostNotificationService and SlackNotificationService to MattermostService and SlackService