nix profile upgrade: unable to upgrade packages via their flake url

[lolbinarycat]

Describe the bug

it is not possible to upgrade a package using the same flake reference you installed it with.

this conflicts with the behavior of every other package manager, where the name used to install and update a package are the same.

it also is a problem when you have multiple packages with the same flake attribute. this is especially common with default packages (packages.x86_64-linux.default)

Steps To Reproduce

1. $ nix profile install nixpkgs#hello
2. $ nix profile upgrade nixpkgs#hello
3. warning: 'nixpkgs#hello' does not match any packages

Expected behavior

the package should be updated

nix-env --version output
nix-env (Nix) 2.18.1

Priorities

Add 👍 to issues you find important.

[bobvanderlinden]

I think this is a duplicate of #10064. This already has an implementation here: #10198, but it isn't being picked up for review yet.