Exposing CA keys in a mine creates a security flaw, thus such
should be avoided.
This change removes code responsible for putting and retrieving
CA key from a mine and changes the ca.sls state to allow configuring
where CA cert and its key would be generated as well as their owners.

Fixes PROD-13439

Change-Id: I6d78b13dcb3754c51606edd7e2d8158e128244a4

Change-Id: Icd6334902ca47d83ae263905d65ef91b8e6a7335

Change-Id: I484f7156dc82ca528307857f41018f4048467f78

Change-Id: I6f1292779858c45f9cf6f4caf3657ee000b2cf06