EE-Port: Circuitbreaker for storage paths

Closes gitlab-com/infrastructure#1946

See merge request !2617

Resolve "Pull repository mirroring: Support for SSH keys"

Closes #98

See merge request !2551

Refactor omniauth controller code

See merge request !2619

EE Port of: Store & use ConvDev percentages returned by Version app

See merge request !2614

[EE] Support group milestone references

See merge request !2612

reverse the conditions in `auditor?`

See merge request !2620

Closes #32207, #33117, gitlab-com/infrastructure#1946, and gitlab-com/infrastructure#1775

See merge request !11449

EE Port of Resolve "Remove jQuery Nicescroll"

See merge request !2608

Audit failed login events

See merge request !2587

Reset only migration models

See merge request !2611

We had a lot of copied and pasted code, when the different elements were very
small and easy to get wrong.

Make contextual sidebar collapsible

See merge request !2616

Geo - Selectively choose which projects to replicate in DR

Closes #2224

See merge request !2533

Allow API access with CI_JOB_TOKEN

Closes #2770

See merge request !2346