Automatic merge from submit-queue

Use secrets for glusterfs provisioning passwords

- no plain password in StorageClass!
- fix the style along the way
- use PV annotations to pass the configuration from provisioners to deleters, inspired by Ceph RBD provisioning.

~~Proposing 1.4:~~

~~- GlusterFS provisioning is a new 1.4 feature~~
~~- if we release GlusterFS provisioner as it is now, we need to support it's API (i.e. plaintext passwords) until 2.0~~
~~- it can break only GlusterFS provisioning, nothing else~~
~~- it's easy to revert~~

@kubernetes/sig-storage

fixes #31871