When sign-in is disabled:
 - skip password expiration checks
 - prevent password reset requests
 - don’t show Password tab in User Settings
 - don’t allow login with username/password for Git over HTTP requests
 - render 404 on requests to Profiles::PasswordsController

This hides/disables some UI elements and API parameters related to
nested groups when MySQL is used, since nested groups are not supported
for MySQL.

Rename `build_events` to `job_events`

Closes #31620

See merge request !11287

This reverts merge request !11287

This commit was about 6 commits before squashing, with the main goal to
make all tests green. Now, after pushing this commit we'll see what the
CI has to say about that.

Fixes gitlab-org/gitlab-ce#28515

[ci skip]

Use strings for the ApplicationSetting properties:
 - restricted_visibility_levels
 - default_project_visibility
 - default_snippet_visibility
 - default_group_visibility

Because environments also expose the project, ensure the projects are
exposed as they were before in API v3.

Instead of exposing the VisibilityLevel as Integer, expose it as
String `visibility`.

 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