Enable pylint checks (#4092)

* pylint: enable checks for imports

* ci: add github action for pylint

* enable pylint on pre-commit

* Install requirements

* use local pylint installation rather than of pre-commit's

* fix import errors

* more checks

* Silence unused imports

* Make a copy of dict

.github/workflows/check-patch.yaml

@@ -0,0 +1,19 @@
+name: Lint Python
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.8
+    - name: Install requirements
+      run: bash ./scripts/ci/install.sh
+    - name: Check Patch
+      run: ./scripts/ci/check_patch.sh