Enhancement - PowerVS Service 'Instance' name/id should be renamed as 'Workspace'

[pravin-dsilva]

What happened:
PowerVS service instances are now called as Workspaces. power-iaas plugin also has this updated naming in 1.0.0 release. It might make sense to update instance-id and instance-name to workspace-id and workspace-name to follow the naming convention in PowerVS

For example: pvsadm image import --instance-name string

What you expected to happen:

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• pvsadm version (use pvsadm version):
• Environment - IBM PowerVS:
• OS (e.g: cat /etc/os-release):
• Kernel (e.g. uname -a):
• Others:

[mkumatag]

@varad-ahirwadkar can you please help us implement this?