"update plugin" context menu in the extension manager is not intuitive

So the "update plugin" context menu does nothing unless you select a different version in the version list. This is not intuitive. That option should:

1. Only show up when you have an update and
2. Should update the plugin to the latest without making me select it from the version list.

Likewise, there's a few other related bugs features here:

1. "Change version" shows up in the extension manager when I have the same version selected which is clearly not the intended case:

If you press it, it will do absolutely nothing.

I think what we should do is remove the upgrade/downgrade button entirely. When the user selects a different version, simply pop up a dialog confirming whether they wish to upgrade or downgrade and then can either accept or cancel. No additional button is needed and then we can...

2. Add an "update plugin" button in the same spot where the previous button is that would behave the same as the context menu and actually just update the plugin.