Merge branch 'feature/gb/pipeline-variable-expressions' into feature/gb/variables-expressions-in-only-except

* feature/gb/pipeline-variable-expressions: (251 commits)

Merge commit '981b5905' into feature/gb/pipeline-variable-expressions

* commit '981b5905': (247 commits)

Keep "Import project" tab/form active when validation fails trying to import  "Repo by URL"

Closes #43261

See merge request gitlab-org/gitlab-ce!17136

Port `read_cross_project` ability from EE

See merge request gitlab-org/gitlab-ce!17208

Add Tip about Push to Create project on New Project page

Closes #42938

See merge request gitlab-org/gitlab-ce!17154

Enable "Legacy Authorization" by default when creating a Cluster on GCP

Closes #41619

See merge request gitlab-org/gitlab-ce!17302

Add a button on the project page to set up a Kubernetes cluster and enable  Auto DevOps

Closes #42431

See merge request gitlab-org/gitlab-ce!16900

Remove bundle tag for ui help

Closes #41341

See merge request gitlab-org/gitlab-ce!17301

GKE 1.8 has RBAC on by default, since GKE has bumped the default version
to 1.8.7 RBAC is now on, and we don't support that out of the box.

This was also avoiding cluster applications (tiller, prometheus, etc), to
be installed.

Closes #41619

Resolve "cache key for CI stopped working"

Closes #43373

See merge request gitlab-org/gitlab-ce!17260

[ci skip]

Use dynamic imports in dispatcher (Part 3)

See merge request gitlab-org/gitlab-ce!17277

Add link to project visibility settings in push to create project docs

See merge request gitlab-org/gitlab-ce!17292

Docs milestones refactor

See merge request gitlab-org/gitlab-ce!17247

Docs: search/replace "Enterprise Edition" and adjust when applicable

See merge request gitlab-org/gitlab-ce!17161

Since the redactor can be run on multiple documents at once and
query results are stored in the request store.