ext: Remove LogWrapper/TestLogWrapper from log.py

ext: Remove LogWrapper/TestLogWrapper from log.py

This patch is removing:

* LogWrapper (wrapping Log)
* TestLogWrapper (wrapping LogWrapper)

There is now a single Log class to be used for logging

JIRA: https://gem5.atlassian.net/projects/GEM5/issues/GEM5-533

Change-Id: I038298565e2ccbe448664a538f888c96fdce8f4a
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/30234
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Hoa Nguyen <hoanguyen@ucdavis.edu>