build(ci): improve PR process (#1015)

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## Description

This PR improves the overall PR creation and checking process.
Particularly it includes the following changes:
- improved the `PULL_REQUEST_TEMPLATE` to have more meaningful
checkboxes that the author needs to check
- added a GitHub workflow to make sure that PR titles follow the
[Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/)
specification


## Checklist
- [ ] Ran Linting
- [ ] Targeted PR against correct branch.
- [ ] Linked to Github issue with discussion and accepted design OR link
to spec that describes this work.
- [ ] Wrote unit tests.
- [ ] Added an entry to the `CHANGELOG.md` file.
- [ ] Re-reviewed `Files changed` in the Github PR explorer.

.github/PULL_REQUEST_TEMPLATE.md

@@ -0,0 +1,24 @@
+## Description
+
+Closes: #XXXX
+
+<!-- Add a description of the changes that this PR introduces and the files that
+are the most critical to review. -->
+
+---
+
+### Author Checklist
+
+*All items are required. Please add a note to the item if the item is not applicable and
+please add links to any relevant follow up issues.*
+
+I have...
+
+- [ ] ran linting
+- [ ] wrote tests where necessary
+- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
+- [ ] targeted the correct branch
+- [ ] provided a link to the relevant issue or specification
+- [ ] reviewed "Files changed" and left comments if necessary
+- [ ] confirmed all CI checks have passed
+- [ ] added an entry to the `CHANGELOG.md` file

.github/workflows/lint-pr.yml

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+name: "Lint PR"
+# Lint PR workflow runs linting over a single PR in order to make sure that the title respects
+# the [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/) specification.
+# This workflow is run every time a PR is opened, edited or updated somehow.
+
+on:
+  pull_request_target:
+    types:
+      - opened
+      - edited
+      - synchronize
+
+jobs:
+  Lint:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Run lint ✅
+        uses: amannn/action-semantic-pull-request@v4.5.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}