Add BuildOption, BuildEnv and PackageOption types

David Rungerequested to merge
dvzrv/buildenv_type into main

Add BuildOption which is a type to track generic option strings that may be prefixed by a "!". Add BuildEnv to track option strings available to a build environment (a wrapper around BuildOption). Add PackageOption to track option strings for packages (a wrapper around BuildOption).

Closes #3 (closed) Closes #8 (closed)

Merge request reports