Having two states that essentially mean the same thing is very much like
having a boolean "true" and boolean "mostly-true": it's rather silly.
This commit merges the "reopened" state into the "opened" state while
taking care of system notes still showing messages along the lines of
"Alice reopened this issue".

A big benefit from having only two states (opened and closed) is that
indexing and querying becomes simpler and more performant. For example,
to get all the opened queries we no longer have to query both states:

    SELECT *
    FROM issues
    WHERE project_id = 2
    AND state IN ('opened', 'reopened');

Instead we can query a single state directly, which can be much faster:

    SELECT *
    FROM issues
    WHERE project_id = 2
    AND state = 'opened';

Further, only having two states makes indexing easier as we will only
ever filter (and thus scan an index) using a single value. Partial
indexes could help but aren't supported on MySQL, complicating the
development process and not being helpful for MySQL.

Use `:empty_project` where possible in feature specs

See merge request !13118

Remove Mattermost team with GitLab group

Closes #30023

See merge request !11362

Global nav (9.0) UI improvement

Closes #34921

See merge request !12772

Support the fact that Gitaly uses bundler

See merge request !13135

[Backport from EE] Refactors GitPushService spec code

See merge request !13148

Backport some recent changes related to LDAP from EE

See merge request !13119

Add remote IP, user ID and username to JSON lograge output

See merge request !13147

Add top-level /merge_requests API endpoint

Closes #28422

See merge request !13060

Resolve "Transform user profile javascript into async bundle"

Closes #35224

See merge request !12929

# Conflicts:
#   config/initializers/lograge.rb

Fix lograge exclusion in params section

See merge request !13146

Display specific error message when JIRA test fails

Closes #32483

See merge request !13100

Merge branch '35667-indicate-type-of-metric-for-prometheus-web-application-monitoring' into 'master'

Indicate type of metric for Prometheus web application monitoring

Closes #35667

See merge request !13142

When destroying a group, now an API call is made to the Mattermost
server to request the deletion of the project. Actual team deletion on
the Mattermost side happens async, so the runtime shouldn't increase by
more than a second.

Fix Prometheus docs to indicate Kubernetes is not required - docs

Closes #35657

See merge request !13140

[ci-skip]

This makes the logs a bit more useful to search requests by users.

Without this fix, we would just see redundant entries in the `params` section:

```
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":404,"duration":1.42,"view":0.38,"db":0.0,"time":"2017-07-28T02:59:18.167Z","params":{"controller":"metrics","action":"index"}}
```

The intended format looks more like this:

```
{"method":"GET","path":"/-/metrics","format":"html","controller":"MetricsController","action":"index","status":404,"duration":76.32,"view":69.95,"db":0.0,"time":"2017-07-28T02:59:48.893Z","params":{}}
```

The proper form to exclude an array is to preface with an asterisk:
https://apidock.com/rails/Hash/except

Add all ApplicationSettings attributes to the API

See merge request !12851

Incorporate RefsService.FindAllBranches Gitaly RPC

Closes gitaly#408

See merge request !13027

Should have been part of !13004.

This matches the behavior of the /issues endpoint.

And add support for additional query parameters:
- `author_id`: Returns merge requests created by the given user `id`
- `assignee_id`: Returns merge requests assigned to the given user `id`
- `scope`: Return merge requests for the given scope: `created-by-me`, `assigned-to-me` or `all`

Remove unused haml file

See merge request !13090

Update server terminolgy to differentiate HA setups from Geo

See merge request !13139