platform/rddaniel: run_model script bug fixes and refactoring

Fix bugs related handling of the model binary path, passing the correct
set of model parameters and handling model launch failuers. While at it,
refactor the handling of parameters for handling automated runs.

Change-Id: Idd014394a0804ac7dbae890a9adff4801b0c7f9e
Signed-off-by: Lokesh B V <lokesh.bv@arm.com>