Initial set up of Main Inference conformance test gen

tosa-verif-build-tests
 - option for setting FP values range
 - option for recursively finding tests
 - change from os.path to Path
tosa_verif_result_check
 - option to supply FP tolerance
 - output difference and max tolerance on contents mismatch
 - change from os.path to Path
MI conformance - contains examples of AVG_POOL2D and CONV2D tests

Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>
Change-Id: I8e1645cd8f10308604400ea53eef723ca163eed7