Make it easier to install 'robotpy official' packages

[virtuald]

Knowing the distinction between pip and opkg is good for advanced users, but vaguely confusing for less advanced users. We should provide a smarter package installation experience that requires less knowledge to do it right.

[virtuald]

I wonder if what we should do create a download/install command that does a search instead of the user specifying -pip or -opkg. I imagine the search order would be something like:

• Prepend python37 to package, check robotpy opkg
• Prepend python37-robotpy, check robotpy opkg
• Check opkg
• Download from pypi as last resort

This would be particularly useful in the case of things that we've built binary wheels for already, but are also present on pip.

[virtuald]

I think we've done a lot towards this, we'll see whether it's easier or not.