CSP compatibility audit

[thibaudcolas]

Summary

An up-to-date review of CSP compatibility issues in Wagtail, with the view to help resolve them all in future releases.

Intended outcome

This will replace the last feature-by-feature review which was 4 years ago. We need a clearer record as we now have CSP on our roadmap and as a GSoC project idea. Aside from auditing, this will involve adding findings in Wagtail issues, or logged to a "CSP compatibility" board in GitHub Projects.

And if there is time, here are stretch tasks on our way to the CSP roadmap item:

• Updating the bakerydemo CSP to be on by default, and document stricter options that are compatible, if possible.
• Updating the developer docs to document current level of CSP support
• Updating guide.wagtail.org or wagtail.org with a CSP

More information

• CSP roadmap item
• CSP compatibility issues
• 2021 feature-by-feature review