Suggested changes for CI and release automation

Splits the npm scripts into primary development tasks and lifecycle scripts:
- `build`
- `precommit`: Rebuilds all generated files
- `prepack`: Lifecycle script to guarantee compiled files are up-to-date before publishing
- `test`
- `version`: Lifecycle script to guarantee all files affected by a version bump are regenerated and added to git

All other scripts are prefixed with `_` to distinguish between the high-level development tasks above and smaller tasks that can be used as building blocks.

Also included in this PR:
- extracted the inline script that would check if any generated files had not been committed to `validate-generated-files.sh`

.github/workflows/integration.yaml

@@ -40,7 +40,7 @@ jobs:
         run: |
           npm ci
           npm run build
-          echo "tough_cookie_tarball=$(npm pack)" >> "$GITHUB_OUTPUT"
+          echo "tough_cookie_tarball=$(npm pack | tail -1)" >> "$GITHUB_OUTPUT"
         working-directory: ./tough-cookie
       - name: Setup HOSTS file for Web Platform Test server
         run: ./test/web-platform-tests/tests/wpt make-hosts-file | sudo tee -a /etc/hosts
@@ -76,7 +76,7 @@ jobs:
         run: |
           npm ci
           npm run build
-          echo "tough_cookie_tarball=$(npm pack)" >> "$GITHUB_OUTPUT"
+          echo "tough_cookie_tarball=$(npm pack | tail -1)" >> "$GITHUB_OUTPUT"
         working-directory: ./tough-cookie
       - name: Setup HOSTS file for Web Platform Test server
         run: ./test/web-platform-tests/tests/wpt make-hosts-file | sudo tee -a /etc/hosts