tmf: log when an error message is displayed in a MessageBox

Provide vital information to external tools such as [1] for testing
purpose. Also allow sharing of error messages a lot more easily.

[1] https://www.eclipse.org/rcptt/

Change-Id: I2dfa6da59c566b0f6a5d55a1d092699c9afcbb26
Signed-off-by: Jonathan Rajotte <jonathan.r.julien@gmail.com>
Reviewed-on: https://git.eclipse.org/r/60860
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-by: Hudson CI
Reviewed-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>
Tested-by: Marc-Andre Laperle <marc-andre.laperle@ericsson.com>