Add programming language setter/getter to HAL

[calcmogul]

This would allow us to have language-specific behavior, like signal handler setup.

[Starlight220]

Shouldn't this be a compile-time (or at least initialization) thing?

[calcmogul]

It can't be compile-time because frcRunRobot.sh determines what robot program, and thus what language, is used.

We could let the user query the language usage reporting we already have.

[ThadHouse]

We also use the same HAL for all languages.

The issue with usage reporting is it happens fairly late. We'd probably want something earlier.