Storagepool SCSI/FC: Implement node devices API backend

In order to implement support to SCSI/FC UI, it is necessary to retrieve
node devices.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>
Storagepool SCSI/FC: API.md entries related to host pci devices

This patch modifies the API.md to list get functions provided by
backend.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>
Storagepool SCSI/FC: Backend implementation

This patch creates functions that allow kimchi users to create an libvirt
SCSI storagepool using the rest API. This patch creates the feature test
to check fc_host capability in libvirt. This patch implements basic
routines to add a disk (scsi) to a new vm template, based on given
volumes (LUN name) from UI or API directly.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>
Storagepool SCSI/FC: Modifies mockmodel and implements tests for FC pool

This patch modifies the Mock model functions to allow user to create a
SCSI FC pool in test environment. Then implements functions to test
API and rest.

Signed-off-by: Rodrigo Trujillo <rodrigo.trujillo@linux.vnet.ibm.com>