Add examine_contents microservice

This new microservice runs a tool which attempts to extract meaningful
patterns and features from files. The primary tool run right now is
bulk_extractor, which is run on disk images and other files alike.

Refs #5880.
Examine contents: add admin option to control

Refs #5880.
wip
WIP UUID instead of description
wip
wip convert more preconfiguredChoices to UUIDs
wip views_processing: fix up key usage
wip views_processing: save settings properly
wip