Migrate Kubernetes service integration templates to clusters

See merge request gitlab-org/gitlab-ce!28534

Updated docs for Merge Trains

See merge request gitlab-org/gitlab-ce!29771

Don't use Kubernetes namespaces with no token

See merge request gitlab-org/gitlab-ce!29643

Add index on invite-email to members

See merge request gitlab-org/gitlab-ce!29768

CE port of "Add test for git http operations for SSO enforced SAML group"

See merge request gitlab-org/gitlab-ce!29550

[CE] Validate page after visit in block

See merge request gitlab-org/gitlab-ce!29524

Expose currently supported events properly on services API

Closes #56737

See merge request gitlab-org/gitlab-ce!29736

Refresh service_account_token for kubernetes_namespaces

See merge request gitlab-org/gitlab-ce!29657

note that todos are not affected by GitLab Notification Email settings

See merge request gitlab-org/gitlab-ce!29539

Hashed Storage is enabled by default on new installations

See merge request gitlab-org/gitlab-ce!29586

Toolbar backport changes for CE

See merge request gitlab-org/gitlab-ce!29758

Merge branch 'ce-backport-11435-mr-search-by-approvers-doesn-t-use-reserved-values-for-none-and-any' into 'master'

Backport fix MR search by approvers

See merge request gitlab-org/gitlab-ce!29621

Backport docs for "Automatically index wikis in elasticsearch"

See merge request gitlab-org/gitlab-ce!29612

Move Dropdown to Stick to MR View App Button

Closes gitlab-ee#12184

See merge request gitlab-org/gitlab-ce!29767

updated documentation for Geo

Visual Review Toolbar Docs

See merge request gitlab-org/gitlab-ce!29641

The dropdown of changed pages in the review app should be attached to
the view app button. This moves it to the correct place. The Review App
button is to the right of both of those.

Disable hooks by setting an ENV var

See merge request gitlab-org/gitlab-ce!29672

Add collapsible sections to job log

See merge request gitlab-org/gitlab-ce!28642

Remove no longer valid password

See merge request gitlab-org/gitlab-ce!29751

Backport the EE schema to CE

Closes gitlab-ee#9686

See merge request gitlab-org/gitlab-ce!26940

CE backport for gitlab-org/gitlab-ee!14064: Add merge train position indicator

See merge request gitlab-org/gitlab-ce!29561

read_repository scope can be used for API

See merge request gitlab-org/gitlab-ce!29663

CE port of IP address restriction for groups

See merge request gitlab-org/gitlab-ce!29467

Fix list rendering on docs site

See merge request gitlab-org/gitlab-ce!29738

One can not upgrade straigt from 9.3 to 12.0, due to the schema changes
being backported. Instead, one must first upgrade to 11.11.X. Omnibus
already enforces this, and our online upgrade guidelines also cover
this.

By changing the CI config we don't have to adjust the backport migration
to handle a migration path that one can not take.

This backports all EE schema changes to CE, including EE migrations,
ensuring both use the same schema.

== Updated tests

A spec related to ghost and support bot users had to be modified to make
it pass. The spec in question assumes that the "support_bot" column
exists when defining the spec. In the single codebase setup this is not
the case, as the column is backported in a later migration. Any attempt
to use a different schema version or use of "around" blocks to
conditionally disable specs won't help, as reverting the backport
migration would also drop the "support_bot" column. Removing the
"support_bot" tests entirely appears to be the only solution.

We also need to update some foreign key tests now that we have
backported the EE columns. Fortunately, these changes are very minor.

== Backporting migrations

This commit moves EE specific migrations (except those for the Geo
tracking database) and related files to CE, and also removes any traces
of the ee/db directory.

Some migrations had to be modified or removed, as they no longer work
with the schema being backported. These migrations were all quite old,
so we opted for removing them where modifying them would take too much
time and effort.

Some old migrations were modified in EE, while also existing in CE. In
these cases we took the EE code, and in one case removed them entirely.
It's not worth spending time trying to merge these changes somehow as we
plan to remove old migrations around the release of 12.0, see
https://gitlab.com/gitlab-org/gitlab-ce/issues/59177 for more details.

This is necessary for backporting the EE schema to ensure backported
foreign keys use the same key names.