Add support for filesystem-only resize

[vojtechtrefny]

Blivet can resize only the filesystem and when filesystem and the underlying block device size don't match we should resize it if the device/volume is referred in the playbook because even if the device has the specified size, the filesystem doesn't so the volume is technically not in the state described in the playbook.

[vojtechtrefny]

It might be enough to simply change this

storage/library/blivet.py

Line 484 in 7c5f8be

if size and self._device.size != size:

to check the format size too, but I didn't test this.

[richm]

@vojtechtrefny is this still an issue?

[richm]

@vojtechtrefny is this still an issue?