Allow "contextual" comments on Drafts

Ability to highlight part of a draft and leave a comment for the specific part.

My team utilizes the shared email features in Front and they are great, but we regularly collaborate on draft emails to a customer. One feature that we regularly use while formulating replies is the "comment". However, this feature is only available for received emails and is missing from drafts.

This would increase our team's internal efficiency a little further, as we would be able to formulate a draft, and comment directly on specific parts in the draft.