* Revert "Sanitize field content in editor"
This reverts commit 1c156905f8.
* Use CSP to block inline JS content in editor
This blocks inline scripts, scripts in the media folder, and
handlers like onclick in the editor. This is nicer than the previous
solution - it doesn't make any permanent changes, and leaves other
content like SVGs alone. Thanks to Nil Admirari for the suggestion.
(cherry picked from commit ddb8573e8d)