Adjusted audit logging for trove.instance module

The trove.instance module is logging some verbose debug data at the
info level, and some info messages at the debug level. Some log
entries are also lacking context because of missing identifiers such
as InstanceID and TenantID.

Changed logging level of various messages to conform to standard,
added references to various ID's as needed.

Change-Id: I3bb569529befa2b2497d2d5a094e3306e569422c
Partial-Bug: #1324206
Merge "Adjusted audit logging for trove.instance module"