Remove Feature logger

Remove Feature logger

This class atttribute is removed as it's quite useless (it forces one
module per project). All messages are now printed to xtesting.log
whatever the namespace and all warnings are printed in console.

Co-Authored-By: Cédric Ollivier <cedric.ollivier@orange.com>
Change-Id: I6860eaf427093ea21b3bd78650bec7939e947b2d
Signed-off-by: Panagiotis Karalis <pkaralis@intracom-telecom.com>
Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
(cherry picked from commit 0249623ab94035ca0ea363d9a86847c2e7a5ee93)