Show the correct icon at low resolution.

This version has updated icons and terminology to make it clearer what the extension is doing.

It also requests permission for all URLs so that it can add a bit of JavaScript to sites so they can detect if the extension is installed. You can see the JavaScript we add here:

https://github.com/mkaply/extended_color_management/blob/main/content-script.js

Updated the messages to be more clear.