[java cmd] Make SelectCommand generic

[rzblue]

This allows users to use any type of map and selector without needing to explicitly match Map<Object, Command>

[PeterJohnson]

It's pretty clearly a breaking change... what does the error message look like if the <> isn't present at the use site?

[Starlight220]

It should be a raw type usage warning -- old code should still compile (Shuffleboard's source code is full of these).

[rzblue]

There's no error message at all when used in a robot project, since we don't enable warnings as errors. It will print a warning, and intellisense will yellow underline it with a recommendation to parameterize it, but neither affects the ability to build and deploy.
And there is no behavior breakage, since the implementation doesn't actually care what the object type is, and java will cast everything to Object internally.