fix name of the loggers used (#10085)

__name__ looks something like `dvc.commands.diff`, but if we are already instantiating
root logger with `dvc`, it adds up to create something like `dvc.dvc.commands.diff`.

We should be using a root logger here instead.

dvc/cli/__init__.py

@@ -12,6 +12,9 @@ from dvc.log import logger
 "".encode("idna")
 
 
+logger = logger.getChild(__name__)
+
+
 class DvcParserError(Exception):
     """Base class for CLI parser errors."""
 

dvc/log.py

@@ -7,4 +7,4 @@ class LoggerWithTrace(logging.Logger):
     trace = logging.debug
 
 
-logger: "LoggerWithTrace" = logging.getLogger("dvc")  # type: ignore[assignment]
+logger: "LoggerWithTrace" = logging.getLogger()  # type: ignore[assignment]