Calls to the v1 API are prefixed with the appropriate version prefix

This will break existing usage in murano-dashboard, where in case if
the murano api host is provided manually, the dashboard explicitly
puts the version number at the end of endpoint
This is fixed in murano-dashboard commit Ic2bbdc6bdd55f1e1d5f7958126ccbad834cbba4c
Closes-bug: #1298477
Change-Id: Idc72c36a36fc2cd57ea02a156838742ace990633