Log project services sidekiq failures

Closes #50528

See merge request gitlab-org/gitlab-ce!21336

Use GitLab UI pagination component for groups

See merge request gitlab-org/gitlab-ce!21287

Update gitlab shell

See merge request gitlab-org/gitlab-ce!21701

Update code_review.md to include a recommendation for assigning maintainers from different teams

See merge request gitlab-org/gitlab-ce!21644

Initialize projects with readme

See merge request gitlab-org/gitlab-ce!21617

Resolve "Markdown footnotes don't render when inside a table..."

Closes #51200

See merge request gitlab-org/gitlab-ce!21675

Improve recommended maintainer docs

Update example Prometheus queries

Closes #49849

See merge request gitlab-org/gitlab-ce!21695

Add trigger information for job API

Closes #50989

See merge request gitlab-org/gitlab-ce!21495

Create new entity called TriggerVariablesEnitity for trigger variables,
to aid reuseablity in the future.

Update JSON schema to include trigger information in the response.

Refactor rspec tests a bit to reduce duplication and for the `context`
to make sense.

closes https://gitlab.com/gitlab-org/gitlab-ce/issues/50989

* Update metric names to match current release.
* Improve descriptions.
* Improve examples to show more query language functionality.

Memory:
* Show use of `or` function.
* Automatically select "MemAvailable" kernel metric if possible.

CPU:
* Show use of `avg without ...`.
* Show CPU utilization per node.

Network:
* Show use of `!=` label matching.
* Don't show "localhost" metrics.

Add GitLab project id to jupyter config installed via cluster apps

See merge request gitlab-org/gitlab-ce!21341

Merge branch '51271-error-500-due-to-encoding-issues-when-when-attempting-to-access-issues-api' into 'master'

Resolve "Error 500 due to encoding issues when when attempting to access issues API"

Closes #51271

See merge request gitlab-org/gitlab-ce!21680

- utilize the 'out' method to output the 'fence_info',
  which converts to utf8
- output 'sourcepos' again

Filter any parameters ending with "key" in logs

See merge request gitlab-org/gitlab-ce!21688

Use gitlab-ui loading icon

See merge request gitlab-org/gitlab-ce!21659

Rails does a partial match for strings in the filter_parameters
configuration, so the parameter "key" causes "key_id" to be filtered
even though it's a useful parameter for debugging internal API issues.

We now revise this filter to make any parameter ending with "key" is
filtered.

Relates to https://gitlab.com/gitlab-com/gl-infra/production/issues/463

Resolve "500 Internal Server Error: Cherrypick commit with empty branch name"

Closes #50677

See merge request gitlab-org/gitlab-ce!21501

Generate JUnit report for Karma tests

See merge request gitlab-org/gitlab-ce!21473

Explicitly use bootstrap 4.1.1

Closes #51362

See merge request gitlab-org/gitlab-ce!21683

Remove unused GlModal import in delete wiki modal

See merge request gitlab-org/gitlab-ce!21677

Fix the group and project activity pages

Closes #51375

See merge request gitlab-org/gitlab-ce!21674

Add empty state illustration information in job API

Closes #51112

See merge request gitlab-org/gitlab-ce!21532

[CE] Fix rails 5 deprecation warnings

See merge request gitlab-org/gitlab-ce!21673

Resolve "[SCSS Variables Cleanup] Combine all duplicated hex colors in variables.scss", Part 1

See merge request gitlab-org/gitlab-ce!21375

Enable frozen string in vestigial files

See merge request gitlab-org/gitlab-ce!21665

Use Rails.root for CommonMetricsImporter

Closes #51333

See merge request gitlab-org/gitlab-ce!21664

Add ability to skip user email confirmation with API

Closes #50876

See merge request gitlab-org/gitlab-ce!21630

Fixes rails 5 deprecation warnings in `config/` files