Support for ICS

[wopu-ot]

EDTT implicitly assumes that certain features are present. This poses problems when testing a configuration that does not follow these assumptions. Support for an ICS as created by LaunchStudio would enable selecting relevant tests automatically and adapt the behavior of test cases. An example for the latter would be that EDTT could check that feature bits are set or cleared according to what is found in the ICS (cf. discussion in #9).

With ICS support in place in EDTT, one could also consider auto-generating an ICS from a Zephyr Kconfig for an automated test flow.