Add endpoint for Jira to request user information

Closes #10752

See merge request gitlab-org/gitlab-ee!10482

Also reduced a bit of duplication and
created a user.json schema file which
is referenced by pull_request.json and
pull_requests.json references
pull_request.json now.
Moved content of "url" field to "html_url"

According to https://developer.github.com/v3/users the "url" field
should contain an api url - not the html url.

Additionally Jira Pull Requests are now showing an avatar of the PR
author.

Add changelog entry

Add missing mr number

Add specs

Expose url of user in url and html_url

I decided against returning an empty string for url (which is,
according to api documentation, supposed to return an api endpoint
instead of a user profile page) but make it return the profile page
as before so the changes won't break any existing code.

Remove extra blank line

Added design management empty state

See merge request gitlab-org/gitlab-ee!10599

Enable ESLint rule jest/no-jasmine-globals

See merge request gitlab-org/gitlab-ce!27137

Enable ESLint rule jest/no-jasmine-globals (EE-port)

See merge request gitlab-org/gitlab-ee!10650

CE backport: Move EE differences for `app/views/admin/users/show.html.haml`

Closes gitlab-ee#6099

See merge request gitlab-org/gitlab-ce!26874

Resolve "Move EE differences for `app/views/admin/users/show.html.haml`"

Closes #6099

See merge request gitlab-org/gitlab-ee!10469

Adds a vendors folder for third party CSS

Closes #59694 and #59708

See merge request gitlab-org/gitlab-ce!27119

Does not run stylelint for the vendors folder

Fixed EE differences in note_body.vue

Closes gitlab-ee#9968

See merge request gitlab-org/gitlab-ce!27126

Fixed EE differences in note_body.vue

See merge request gitlab-org/gitlab-ee!10644

Remove EE-specific changes from FilteredSearchBoards (CE-backport)

See merge request gitlab-org/gitlab-ce!27122

Remove EE-specific changes from FilteredSearchBoards

Closes #10018

See merge request gitlab-org/gitlab-ee!10642

(cherry picked from commit e658b337)

(cherry picked from commit cb892da6)

(cherry picked from commit b28ba16a)

Resolve "Extract EE specific files/lines for CI/CD spec/requests/api"

Closes #6669

See merge request gitlab-org/gitlab-ee!10656

Revert "Merge branch 'fix-ide-web-worker-relative-url' into 'master'"

Closes #60217

See merge request gitlab-org/gitlab-ce!26066

Set Release Name When Adding Release Notes to an Existing Tag

Closes #58418

See merge request gitlab-org/gitlab-ce!26807

Also set the release sha and author

This reverts merge request !26015

Name GitLab managed apps

See merge request gitlab-org/gitlab-ce!27129

QA: Change CI value to something that can be masked

See merge request gitlab-org/gitlab-ce!27146

Docs: Update predefined_variables.md to fix anchor

See merge request gitlab-org/gitlab-ce!27127

Update Okta configuration notes

See merge request gitlab-org/gitlab-ce!27076