[CE] Backport SAML settings changes (Adds validators and rack cookie helper)

See merge request gitlab-org/gitlab-ce!18033

These changes are backported from EE, related to SAML settings in
https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4549

Resolve "Migrate upload task fails for Groups"

Closes #44776

See merge request gitlab-org/gitlab-ce!18088

Bump html-pipeline to 2.7.1

Closes #24039

See merge request gitlab-org/gitlab-ce!18132

Update docs for API for issue and merge request description templates

See merge request gitlab-org/gitlab-ce!18114

Redesign application settings to match project settings (part 3)

See merge request gitlab-org/gitlab-ce!18056

Pipeline variables expression in only/except configuration

Closes #37397

See merge request gitlab-org/gitlab-ce!17316

Resolve "Usage ping for Kubernetes integration"

Closes #44291

See merge request gitlab-org/gitlab-ce!17922

Basic Setup for MR Showing

Closes #44840 and #44839

See merge request gitlab-org/gitlab-ce!17952

Merge branch 'theothertom/gitlab-ce-bug/42663/update-jira-integration-docs-for-new-jira-UI-docs' into 'master'

Update Jira integration docs for new Jira UI

Closes #42663

See merge request gitlab-org/gitlab-ce!18107

Extend API for exporting a project with direct upload URL

Closes #42685

See merge request gitlab-org/gitlab-ce!17686

Add closed by information to issue API

See merge request gitlab-org/gitlab-ce!17042

Add changelog entry for rake task fix

See merge request gitlab-org/gitlab-ce!18112

Free open file descriptors and libgit2 buffers in UpdatePagesService

See merge request gitlab-org/gitlab-ce!18099

Don't let the Runner clone/fetch prior to the package-and-qa job

See merge request gitlab-org/gitlab-ce!18102

Resolve "Migrate upload task fails for Upload with `store: nil`"

Closes #44774

See merge request gitlab-org/gitlab-ce!18082

Resolve "doc/api/jobs.md should be harmonized between CE and EE"

Closes #44835

See merge request gitlab-org/gitlab-ce!18106

Do it by hand instead, that way we can still run this job even if the
branch has been removed.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Updating runner docs to add specific runner to projects from the admin area-doc

See merge request gitlab-org/gitlab-ce!17585

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

Tweak restore rake task to provide an option to set alternate temporary backup directory

Closes #42593

See merge request gitlab-org/gitlab-ce!17516

Update no repository placeholder

See merge request gitlab-org/gitlab-ce!17964

Add gitlab-pages port number to artifacts links, if needed

Closes #44398

See merge request gitlab-org/gitlab-ce!18073

Update charlock_holmes to 0.76

See merge request gitlab-org/gitlab-ce!18103

Update dashboard milestones breadcrumb link

See merge request gitlab-org/gitlab-ce!17933

Didn't compile against newer icu4c versions and was fixed upstream in
https://github.com/brianmario/charlock_holmes/pull/129, which was
releaed in the versions its now locked to.

Document that LFS is included in the 10GB repository limit on gitlab.com

See merge request gitlab-org/gitlab-ce!18093