[sled-agent] Fail loudly if virtual hardware has not been instantiated correctly #1049
Description
The sled agent currently tries to initialize the xde driver with some underlay devices, which are VNICs created by a call to ./tools/create_virtual_hardware.sh. Additionally, the driver expects a configuration file that was not correctly shipped with the actual pkg repository for the driver.
In any of these cases, the sled agent should fail loudly and with clear error messages about how to proceed.