Allow installing a backend from a URL

[TomAFrench]

Problem

We need a good way to install different backends through nargo.

Happy Case

For an MVP we can allow a user to provide a backend name and an install url which serves a zipped tarball.

nargo backend install <backend name> <backend url>

This will create a directory in ~/.nargo/backends for this new backend which will hold any backend specific files (binary, crs, etc.)

If we're allowing installing through from a URL, we need to define a standard for how the backend binary should be contained within the tarball. For instance we currently assume that the binary will be the only file in the archive and that it exists at the root.

Alternatives Considered

No response

Additional Context

No response

Would you like to submit a PR for this Issue?

No

Support Needs

No response

[TomAFrench]

Addressed by #2575