Run CI in Github Actions (#22054)

* Tidy workflows

* Update get-version-from-git.sh

* Run tests in Actions

* Upload coverage to SonarCloud

* Run linters in Actions

* Run builds in Actions, consolidating with sentry uploader

* Update sonar-project.properties

* chmod +x

* Iterate

* Use new env vars

* Delete yarn-sub.js

* Use re-usable sonarqube action

* Add README badges

* Match reality

.github/workflows/tests.yaml

@@ -0,0 +1,37 @@
+name: Tests
+on:
+  pull_request: { }
+  push:
+    branches: [ develop, master ]
+  repository_dispatch:
+    types: [ element-web-notify ]
+env:
+  # These must be set for fetchdep.sh to get the right branch
+  REPOSITORY: ${{ github.repository }}
+  PR_NUMBER: ${{ github.event.pull_request.number }}
+jobs:
+  jest:
+    name: Jest
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Yarn cache
+        uses: actions/setup-node@v3
+        with:
+          cache: 'yarn'
+
+      - name: Install Dependencies
+        run: "./scripts/layered.sh"
+
+      - name: Run tests with coverage
+        run: "yarn coverage --ci"
+
+      - name: Upload Artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: coverage
+          path: |
+            coverage
+            !coverage/lcov-report