feat: Expose installed binaries under PATH for custom packages

[isidentical]

Requires #44 first!

[chamini2]

ATL: So this is to enable users to have access to any system package in the environments created? Normally added through conda

[isidentical]

So this is to enable users to have access to any system package in the environments created? Normally added through conda

Yep! More like any binary package they have in particular environments, since they already did have access for system packages (the PATH was inherited from the parent process's session in the past, which would mean they had access to everything that the initial shell does). One example is fal, e.g. if we install fal in an isolate environment (not just conda, but virtualenv too) and try to do a subprocess.run(["fal"]) it now works (i don't think it did work in the past, since there were no fal executable in your PATH) since we expose it to your session.