python: do not override root logger (#7743)

By adding a handler for `""`, we were effectively pushing all logs to a
file, including the user's. I've removed the root logger and instead
added a few other handlers to capture logs.

**_This change does expose us to a much higher likelihood of our logs
leaking into the console._**

Eg, the added handlers were after observing
`positron._vendor.pygls.protocol.json_rpc` will send out logs if you run
something like `import xyzabc`, and the `Comm` logs were leaking if
there is an error in the comms.

Related issue in Jupyter, where they needed to handle `tornado` logs
jupyter/notebook#1397

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#### New Features

- N/A

#### Bug Fixes

- #4182 Python users' logs are now sent to console.


### QA Notes

```python

import logging
logging.warning("should show")
```

it's worth it to try to force a few other errors, to make sure we don't
need to add other handlers.

Author: isabelizimm

extensions/positron-python/python_files/posit/positron_language_server.py

@@ -90,11 +90,15 @@ def parse_args() -> argparse.Namespace:
     handlers = ["console"] if args.logfile is None else ["file"]
     logging_config = {
         "loggers": {
-            "": {
+            "PositronIPKernelApp": {
                 "level": args.loglevel,
                 "handlers": handlers,
             },
-            "PositronIPKernelApp": {
+            "Comm": {
+                "level": args.loglevel,
+                "handlers": handlers,
+            },
+            "positron": {
                 "level": args.loglevel,
                 "handlers": handlers,
             },