device_config: added module to handle Device Configurations
device_config: added module to handle Device Configurations

For now, the module only adds configurations for Block Devices.
The plan is to add all device configuration related structures
in this module.

The BlockDeviceConfigurations is a linked list of Block Devices
in which the first element is always the root device (if one is
present).

Signed-off-by: Andreea Florescu <f68a7d732e796861f8e79ea704b43a5ee52eddaf@amazon.com>

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