Allow us to see and install untrusted plugins in the toolbox

It is currently impossible to install unendorsed plugins from the toolbox.

Currently, the toolbox-service API for plugins will only return Roblox endorsed plugins, while this is generally helpful, this drastically slows me down if the plugin im looking for isn’t endorsed (cough legacy surface tool), since it forces me to close Studio, navigate to the Library page, and install that way.

I say it should be hidden behind a setting in the toolbox (or even an FFlag to make it a power user thing).

This would improve my development experience because it means I wouldn’t have to close Studio to install some plugins.