Add type hints

[ale-rt]

Initial draft courtesy of monkeytype:

.venv/bin/uv pip install -e plone.base[test] monkeytype zope.testrunner
monkeytype run .venv/bin/zope-testrunner --path plone.base/src/
for module in `monkeytype list-modules`; do monkeytype apply $module || true > /dev/null;done

• I signed and returned the Plone Contributor Agreement, and received and accepted an invitation to join a team in the Plone GitHub organization.
• I verified there aren't any other open pull requests for the same change.
• I followed the guidelines in Contributing to Plone.
• I successfully ran code quality checks on my changes locally.
• I successfully ran tests on my changes locally.
• If needed, I added new tests for my changes.
• If needed, I added documentation for my changes.
• I included a change log entry in my commits.

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If your pull request closes an open issue, include the exact text below, immediately followed by the issue number. When your pull request gets merged, then that issue will close automatically.

Closes #

[mister-roboto]

@ale-rt thanks for creating this Pull Request and helping to improve Plone!

TL;DR: Finish pushing changes, pass all other checks, then paste a comment:

@jenkins-plone-org please run jobs

To ensure that these changes do not break other parts of Plone, the Plone test suite matrix needs to pass, but it takes 30-60 min. Other CI checks are usually much faster and the Plone Jenkins resources are limited, so when done pushing changes and all other checks pass either start all Jenkins PR jobs yourself, or simply add the comment above in this PR to start all the jobs automatically.

Happy hacking!

[ale-rt]

@jenkins-plone-org please run jobs