feat: add dom-purify to tiptap editor update

[bddjong]

• Add dom purify
• Test output is still the same
• Test output is sanitized if needed (need to check how to test this, what's supposed to be sanitized)
• Investigate how how to sanitize the JSON save option (we don't use it but the code path exists now.)

[bddjong]

Tested that its (at least partially) working by temporarily stripping data-attributes. Potentially XSS href's arent being stripped correctly though. I suspect the output is already escaped at the point where dom-purify is implemented now, which could cause it to just ignore it.