chore: add tests for install-receipts from sh

[Gankra]

fixes #773

[Gankra]

TODO:

• check if we really want ~/.cargo/ and not ~/.cargo/bin/ in the install receipt
• pick a "good" seperator for the sed (currently stubbed to ~) ((or better escaping?))

[mistydemeo]

check if we really want ~/.cargo/ and not ~/.cargo/bin/ in the install receipt

We do, yes. While we're likely to only install binaries, in the future we'll be installing other kinds of files - libraries, config files, etc. These are installed in other subdirectories inside the install prefix.