MLECO-5564: Adding interactive mode

* This patch allows user to press a key to continue
  to the next inference controlled by a new
  CMake config option - INTERACTIVE_MODE.
* This is useful when terminal or LCD output needs
  to be inspected before continuing to the
  next inference
* Simplified stdout component and removed redundant
  method

Change-Id: I0d4b65ce82292606a31fa89fe47b7d86aa3c27e7
Signed-off-by: Vivek Choradia <vivek.choradia@arm.com>
Signed-off-by: Alex Tawse <alex.tawse@arm.com>