Add build script

[wszdexdrf]

I believe this should be all that is needed. I don't think we can install OS-level dependencies. For udev rules, it is possible but then we would have to duplicate/include_str the install_udev_rules() function in build.rs

[afilini]

I don't think using build scripts is the best way to do this: our goal is to install hwi on the user's machine, not the builder's.

I think the best way is to expose a couple of functions, one to check if hwi is available (also checking its version) and one to install it. Then I would leave it up to the user of this library to call those functions whenever they want.

Most of the time I would expect hwi to be packaged together with the rust binaries in some ways: when using package managers like apt or rpm you could just add the python hwi as a dependency of your package. Alternatively when building a wallet into an AppImage you can probably bundle hwi in there as well.

[danielabrozzoni]

Once this is updated, I can ACK, merge and tag the new version (needed for bitcoindevkit/bdk#682) - no rush tho :) We can totally start reviewing #682 before rust-hwi is published, you can just use rust-hwi master in the meantime

[danielabrozzoni]

utACK 589c3cf