Improve DCAE APP Simulator coverage

Also there was a need to refactor the code, because application logic
was placed inside Ratpack handlers.

Change-Id: Iba3d4d039a98ba88e0dba580c1b7726b53440538
Issue-ID: DCAEGEN2-732
Signed-off-by: Piotr Jaszczyk <piotr.jaszczyk@nokia.com>
22 files changed