feat: add back the capturing of logs from logging

[bepri]

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This PR brings back Craft CLI's integration with the logging library. To do this, a shim class is defined in craft_cli/_logs.py in order to inherit from logging.Handler. This class wraps a LogListener class defined in Rust that actually parses logging events and sends them to the printer.

Here's a quick script for testing the feature:

#!/usr/bin/env python3
"""e."""
import logging
import subprocess

from craft_cli import EmitterMode
from craft_cli._rs.emitter import Emitter

logger = logging.getLogger(__name__)

e = Emitter("blah.log", EmitterMode.VERBOSE, "example.com", "Hello")

logger.info("Testing")
with e.open_stream() as pipe:
    for i in range(5):
        logger.debug("Printing %d", i)
        subprocess.run(["echo", str(i)], check=True, stdout=pipe)

e.message("Done")

I discovered a bug while testing where BRIEF verbosity will often clear one too many lines of your terminal, but it isn't related to these changes.

[bepri]

I keep this so Python doesn't deallocate it.

[bepri]

If this returns None, it's because we decided that log capture wasn't necessary for this run's verbosity level.

[bepri]

This intern! macro is just a cheap optimization trick PyO3 provides. Instead of having to coerce the Rust "levelno" string into Python for every logging event, intern! keeps a copy of this string on Python's heap after the first call.

[bepri]

This is separated out from Quiet because Brief mode can require log handling if streaming_brief is enabled, which will be the next PR.