feat: add hare language support

[onemoresuza]

The module, besides providing the Hare binary through devshell.packages, exposes the following options:

1. thirdPartyLibs: add hare third-party libraries (pkgs.hareThirdParty) to the HAREPATH environment variable.
2. vendoredLibs: add vendored libraries (any path on the project repo) to HAREPATH.
3. package: set which hare package to use (defaults to pkgs.hare).

Regarding third-party libraries, the module also takes care of the ones included on propagatedBuildInputs, by adding them to HAREPATH.