CP-4325: Implement pool.get_license_state

Signed-off-by: John Else <john.else@citrix.com>
CP-4325 Add pool.license_state getter to CLI

Signed-off-by: John Else <john.else@citrix.com>
Add Test_common.make_pool

Signed-off-by: John Else <john.else@citrix.com>