[GitHubChecksStatus] Add commit check badge (#5973)

* Add GH commit check badge

* Fix class name, tests

* Run prettier

* Refactor to generic checks

* Run prettier

* Make keywords separate from title

* Make commit failing tests actually fail

* Resolve suggested edits

* Sanitize imports

* Follow import order requirements

Co-authored-by: repo-ranger[bot] <39074581+repo-ranger[bot]@users.noreply.github.com>

services/github/github-checks-status.tester.js

@@ -0,0 +1,19 @@
+'use strict'
+
+const t = (module.exports = require('../tester').createServiceTester())
+const { isBuildStatus } = require('../build-status')
+
+t.create('branch checks (branch)')
+  .get('/badges/shields/master.json')
+  .expectBadge({
+    label: 'checks',
+    message: isBuildStatus,
+  })
+
+t.create('checks - nonexistent ref')
+  .get('/badges/shields/this-ref-does-not-exist.json')
+  .expectBadge({
+    label: 'checks',
+    message: 'ref or repo not found',
+    color: 'red',
+  })