cli: allow filtering by log stream

[maminrayej]

Extends the app logs command to allow filtering different log streams.

Closes #4412 / RUN-69

[ayys]

@maminrayej Do you think it makes sense to do it like wasmer app logs --streams [stdout|stderr|all]? with all being the default.

[maminrayej]

I think your suggestion of allowing the user to list the desired streams is better. It's going to be a little bit more awkward to parse, but I think it's worth it since if any more streams get added in the future, having --stream1 --stream2 --stream3 is ugly.

But I'm not the biggest fan of | between options. I prefer:

wasmer app logs --streams stdout, stderr

It's similar to how you can specify a set of features in Cargo:

cargo build --features "feature1, feature2"

What do you think?

[theduke]

We can potentially do this in a followup PR, but we should also allow client-side sorting of logs into streams.

And also allow filtering by instance ID.
I'm not sure if that was a separate issue or not.