This UI should be able to tell me what the base version of the selected path is, what packages are installed and what versions they are before I add it to my project.

It could also include an MRU list (maybe just for envs outside of $(ProjectHome)) and the autodetected interpreters. (Adding the autodetected interpreters removes the need to ever deactivate envs and is better than the existing UI for selecting an interpreter. It will also let us share pip support between the features.)