Warn if user opens old version of VS Code

[sciencewhiz]

Since we install multiple year's VS Code independently, there have been cases where people accidentally open an old version (I've done it too). Here's one example https://www.chiefdelphi.com/t/phoenix-library-linking-errors/422052/4

It might be nice if there was a prompt that an old version was opened. A naive way would be to look at current date and if it's plugin version + a year to warn. Could also look for the existance of ~/wpilib/year+1 or something on maven or gradle plugin portal.

Probably want a way to permanently turn it off too.