Added new API microversion which allows the following:
- add tag to the server
- replace set of server tags with new set of tags
- get information about server, including list of tags for server
- get just list of tags for server
- check if tag exists on a server
- remove specified tag from server
- remove all tags from server
- search servers by tags
DocImpact
APIImpact
Implements: blueprint tag-instances
Change-Id: I9573aa52aae9f49945d8806ca5e52ada29fb087a