Transition from document.execCommand to navigator.clipboard

[vincentdo]

💥 Proposal

Is your feature request related to a problem? Please describe
document.execCommand is being deprecated. navigator.clipboard.readText and writeText are already supported in all browsers so we should be able to just replace the implementation.

Describe the solution you'd like
Replace document.execCommand with navigator.clipboard.readText/writeText

Describe alternatives you've considered
None

Are you able to assist to bring the feature to reality?
I can try

Additional context
https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Interact_with_the_clipboard

Have you read the Contributing Guidelines on issues?

Yes