build: add CodeQL analysis

.github/workflows/codeql-analysis.yml

+name: "CodeQL"
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    # The branches below must be a subset of the branches above
+    branches: [master]
+  schedule:
+    - cron: '0 9 * * 5'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        language: ['java']
+
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v1
+      with:
+        queries: +security-extended
+        languages: ${{ matrix.language }}
+
+    # Don't build tests in jadx-core also skip tests execution and checkstyle tasks
+    - run: |
+        ./gradlew clean build -x checkstyleTest -x checkstyleMain -x test -x ':jadx-core:testClasses'
+
+    - name: Perform CodeQL Analysis
+      uses: github/codeql-action/analyze@v1