Make it easy for site builders to send HTML formatted emails

Ah, just found 🌱 [META] Adopt the symfony mailer component Needs review

This is not controversial and IMO does not need to pass the ideas phase. This should just be a meta issue in the core queue.

I suppose it's best to close this a duplicate of 🌱 [META] Adopt the symfony mailer component Needs review since there is a plan in that issue to work towards this goal.

Added correct maintenance statuses for Mime Mail. Not sure why they were listed as "?", because this information is easily obtainable from the project page.