Port of protected environments frontend changes from EE to CE

See merge request gitlab-org/gitlab-ce!21018

Add group milestones to dashboard milestone page

Closes #35748

See merge request gitlab-org/gitlab-ce!20618

Resolve "Commit messages are no longer monospace, but still white-space: pre-wrap"

Closes #47548

See merge request gitlab-org/gitlab-ce!20988

Parse junit.xml.gz and calculate the difference between head and base

See merge request gitlab-org/gitlab-ce!20576

Rails5: update Rails5 lock for forgotten gem rouge

See merge request gitlab-org/gitlab-ce!21010

Update proofreader.md

See merge request gitlab-org/gitlab-ce!20985

Merge branch '46940-hashed-storage-extend-enable-hashed-storage-for-all-new-projects-to-for-all-new-and-renamed-projects' into 'master'

Resolve "Hashed storage: extend "Enable hashed storage for all new projects" to "for all new and renamed projects""

Closes #46940

See merge request gitlab-org/gitlab-ce!19747

Resolve "Hashed storage: extend "Enable hashed storage for all new projects" to "for all new and renamed projects""

Resolve "Pipeline job log page uses too much CPU for loading animation"

Closes #49776

See merge request gitlab-org/gitlab-ce!20915

Enable frozen string for app/models/**/*.rb

See merge request gitlab-org/gitlab-ce!21001

Frontend code for "JUnit XML Test Summary In MR widget"

See merge request gitlab-org/gitlab-ce!20936

Fix spec warnings and template helper

See merge request gitlab-org/gitlab-ce!21007

Improve blocked user tracking and fire some events only once

Closes #49784

See merge request gitlab-org/gitlab-ce!20959

Resolve "Merge request e-mail link has full URL"

Closes #49899

See merge request gitlab-org/gitlab-ce!21000

Update query simplification

Closes #49873

See merge request gitlab-org/gitlab-ce!20982

Signed-off-by: Rémy Coutable <remy@rymai.me>

Resolve "Unicorn development settings should match production as much as possible"

Closes #49756

See merge request gitlab-org/gitlab-ce!20919

Enable renaming files & folders in the Web IDE

Closes #44845

See merge request gitlab-org/gitlab-ce!20835

Removed obsolete note about manual uploads migration

Closes #49239

See merge request gitlab-org/gitlab-ce!21002

Set default timeout for deleting many refs

Closes #49862

See merge request gitlab-org/gitlab-ce!20974