Use DiskSettings instead of devicePath in resolvers

* GetRealDevicePath
* MountPersistentDisk
* UnmountPersistentDisk
* NormalizeDiskPath
Add VirtioDevicePathResolver

Resolve disk path first by id, then by path
Move udevdevice to platform
Use udevdevice in id path resolver
VsphereDevicePathResolver -> ScsiDevicePathResolver

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Add Trigger to udevdevice

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Trigger udev before resolving path by id

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
fs Readlink returns absolute path

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>
Id path resolver checks for ID format

Signed-off-by: Maria Shaldibina <mshaldibina@pivotal.io>