ewaol-tests: Add additional log information

This patch adjusts the test logging to:
* Output the location of the log file to the terminal on test failure
* Add a clean-up category to the log messages to clarify which messages relate
  to the tests and which relate to surrounding environment clean-up activities
* Ensure all arguments to the log function are recorded

Issue-Id: SCM-3042
Signed-off-by: Richard Neill <richard.neill@arm.com>
Change-Id: I92bc776cb6c9d428ec6bbf2c0cd59aa3803d16ac