There are many place where server POST request has been used to tests
other API behavior. There was issue of having duplicate
server POST req and resp sample files in each API sample directory.
we added logic to share those sample files from common place
('servers' sample dir)
As microversion tests also need to share such logic, This commit
extends that logic to work for microversion tests also.
Partially implements blueprint test-collapse-v2-and-v21
Change-Id: I3448e1934585c2dabed6c45216ea0513db258b27