Update OSTF deployment tags to use Sahara

Updated OSTF deployment tags so that they mention
Sahara instead of Savanna. Updated adapter mixins
method to get correct deployment tags when using
Sahara component.
Corrected messages in tests that mention Savanna
so that they use Sahara.

Change-Id: I6c64fa7cd5d67f0640d045ae4ebd8ac07a6bce47
Closes-Bug: #1300125