Add a parameter to control whether compression is performed when creating volumesnapshots.

[cncal]

Is your feature request related to a problem?/Why is this needed

I stores some large compressed files with PVCs. Creating volumesnapshot would compress those files again that is very time-consuming and the compression effect is quite limited.

Describe the solution you'd like in detail

Add a driver parameter to control whether compression is performed when creating volumesnapshots. If no compression，snapshot-controller would do tar (untar) without -z when creating (restoring) a volumesnapshot.