Created one configuration .json file for boards with internal
wifi (HeapBlockDeviceAndWifiInterface.json). Removed dedicated
Odin, Wiced and Realtek wifi configuration files. Removed Odin
ethernet configuration file and replaced that with general
ethernet configuration.
Not all devices have enough heap to fit a simulated heap block device,
however using a simulated heap block device is preferred if available
(reduced flash wear, faster testing).
Added MBED_TEST_SIM_BLOCKDEVICE for tests that only need a simulated
block device (wear_leveling + resilience), and added support for targets
that are known to have enough heap.
Tools will figure out if user passed in a custom path (to indicate configration file for module) or whether they used a keyword (to indicate they'd like to use an mbed OS configuration)