chore: add info messages to solc install/compile

[odyslam]

Add informational messages to solc installation and compilation.

The compilation of a project could give the appearance of a hanging program because of downloading and installing solc. Informational messages allow the user to know what's happening and why it might take more than expected.

[gakonst]

LGTM for the download step, no need to add extra info elsewhere imo, as one may want to have more control over that message

[mattsse]

I'm leaning against this for the simple reason that this is a foundry use case and ethers-solc is a standalone crate that ideally should not print anything unconditionally.

A better solution imo would be to have something like

pub trait SolcProgressMonitor {
   fn on_install(version: &Version) {}
   fn on_installed(version: &Version) {}
   fn on_compile(input: &CompilerInput) {}
}

we could then do something similar to how logging works in general
basically using a global SolcProgressMonitor that calls the callbacks.
This global instance (static mut) can then be instantiated with a StdOutProgressMinitor implementation for example.

this way the user can control, if and how things are logged.

But for the time being this is perfectly fine

[odyslam]

@mattsse -- The reason I made the contributions here is that all these steps are exposed via a single function call in the forge build, as far as I understood it.

[gakonst]

@mattsse agree on the hook for logging to stdout, good idea.