Evaluate the possibility of a conditional compilation flag for `nonportable` behaviour.

[LFS6502]

Evaluate if this is worth it to add a compilation flag for the nonportable behaviour.

A) It could continue using a filesystem check for a file called nonportable in the bin's parent directory.

This would allow the packages for v1 to continue using /opt as the installation directory. However this feels like a hacky solution.

B) Implement a compilation flag for the nonportable behaviour.

This would allow the binary to live in the system's binaries directory (such as /usr/bin). However, this requires publishing 2 versions of the binary on github releases, one with the feature enabled, and the other one with the feature disabled.