This reverts merge request !20679

Resolve "Making instance-wide data tools more accessible"

Closes #41416 and #48507

See merge request gitlab-org/gitlab-ce!20679

CE: Add PolicyCheckable concern for things passing to policy check

See merge request gitlab-org/gitlab-ce!20839

if all methods are also presented in the user.

Resolve "The comparison list for the modified icons"

Closes #48567

See merge request gitlab-org/gitlab-ce!20501

More Gitaly cleanup: fetch_ref, allow disk access blocks

Closes gitaly#1295

See merge request gitlab-org/gitlab-ce!20802

Rails5 update Gemfile.rails5.lock

See merge request gitlab-org/gitlab-ce!20858

[master] Escapes milestone title shown in flash message when promoting a milestone

See merge request gitlab/gitlabhq!2436

[master] Fixed XSS in branch name in Web IDE

See merge request gitlab/gitlabhq!2431

[master] Escapes job name used in tooltips

See merge request gitlab/gitlabhq!2427

[master] Missing CSRF in System Hooks

See merge request gitlab/gitlabhq!2419

Fix namespace move callback behavior, especially to fix Geo replication of namespace moves during certain exceptions

Closes gitlab-ee#6252

See merge request gitlab-org/gitlab-ce!19297

Fix namespace move callback behavior, especially to fix Geo replication of namespace moves during certain exceptions

Resolve "BS4: Link in code brackets has two different styles"

Closes #48542

See merge request gitlab-org/gitlab-ce!20841