.github: Add codeql scanner

See also: https://docs.github.com/en/code-security/secure-coding/configuring-code-scanning

Configuration taken from: https://github.com/github/codeql-action/blob/main/README.md#usage

.github/workflows/codeql-analysis.yml

@@ -0,0 +1,54 @@
+name: "Code Scanning - Action"
+
+on:
+  push:
+    branches:
+     - master
+     - v*
+  pull_request:
+  schedule:
+    #        ┌───────────── minute (0 - 59)
+    #        │  ┌───────────── hour (0 - 23)
+    #        │  │ ┌───────────── day of the month (1 - 31)
+    #        │  │ │ ┌───────────── month (1 - 12 or JAN-DEC)
+    #        │  │ │ │ ┌───────────── day of the week (0 - 6 or SUN-SAT)
+    #        │  │ │ │ │
+    #        │  │ │ │ │
+    #        │  │ │ │ │
+    #        *  * * * *
+    - cron: '30 1 * * 0'
+
+jobs:
+  CodeQL-Build:
+    # CodeQL runs on ubuntu-latest, windows-latest, and macos-latest
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      # Initializes the CodeQL tools for scanning.
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v1
+        # Override language selection by uncommenting this and choosing your languages
+        # with:
+        #   languages: go, javascript, csharp, python, cpp, java
+
+      # Autobuild attempts to build any compiled languages (C/C++, C#, or Java).
+      # If this step fails, then you should remove it and run the build manually (see below).
+      - name: Autobuild
+        uses: github/codeql-action/autobuild@v1
+
+      # ℹ️ Command-line programs to run using the OS shell.
+      # 📚 https://git.io/JvXDl
+
+      # ✏️ If the Autobuild fails above, remove it and uncomment the following
+      #    three lines and modify them (or add more) to build your code if your
+      #    project uses a compiled language
+
+      # - run: |
+      #   make bootstrap
+      #   make release
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v1