storage: Properly resize a local volume using LUKS

storage: Properly resize a local volume using LUKS

https://bugzilla.redhat.com/show_bug.cgi?id=1490279

Turns out the virStorageBackendVolResizeLocal did not differentiate
whether the target volume was a LUKS volume or not and just blindly
did the ftruncate() on the target volume.

Follow the volume creation logic (in general) and create a qemu-img
resize command to resize the target volume for LUKS ensuring that
the --object secret is provided as well as the '--image-opts' used
by the qemu-img resize logic to describe the path and secret ensuring
that it's using the luks driver on the volume of course.