[Feature] Refresh addon data

[Sephiroth018]

It would be nice to have some kind of refresh button to:

• Check for updates
• Refresh "Find more" tab
• Rescan for installed addons

For now, I have to restart minion to do this and that's really annoying when you only want to check if there is a new update for addon xy, after finding a bug that could already be reported by others, or you want to browse through the available addons while waiting for something (a "last updated on" and "first uploaded on" filter would be nice for this, and as far as I have seen, at least the latter one is already planned ).