Chat mode!

Added a chat mode!

1.10

Perofrmance boost, less mucking around with DOM so less reflows
Code cleaner
Actually use some modern JS

1.9

Auto select last used model

1.8

Fix bug when showing non-standard models.

1.7

Add translate default option
Clear storage between use

1.6

Improvements to stability
Settings link now in Aify menu
Draft page now shows loading status and has a regenerate button

1.5

Add in API to pull available models
Improve UX styling and clarity

1.4

Add in length control to reponses to manage token count.
Add in more reactive buttons to settings page.

1.3

Make settings page clearer with instructions and layout

1.1

Also on addon store
https://addons.thunderbird.net/en-US/thunderbird/addon/aify/