Add hostname to TriggerEvent

TriggerEvents are going to need to store information to fully-qualify
projects.  Yet, most of their use is within the context of a driver, so
make sure that we can easily access both the fully-qualifed and
unqualified project name.

Change-Id: I06c6fbe361c23b0d6fb3dda3344fc58339bafefb
Story: 2000953
5 files changed