Rename instance_actions v3 plugin tests to server_actions

* Renames the os-instance_actions v3 plugin tests to os-server-actions
* Also modifies JSON v3 client to use os-server-actions
* Skip get_server_actions and list_server_actions json tests
* This is required because changing name of v3 ext os-instance-actions
* to os-server-actions.

Closes-Bug: #1206032

DocImpact

Required-By: Id5049e10f5ef540d0d8e3871d800e9d9cb33da73

Change-Id: Ia493d4838dee4a8a587d12a55f16afeb143d959d
Merge "Rename instance_actions v3 plugin tests to server_actions"