Refactored skill framework and added new enum classes so that a skill can not return idle or running as terminating value

to timestamp) (FR)

Signed-off-by: Rainer Kartmann <rainer.kartmann@kit.edu>

Fix bug in Object Memory, where it does not recover from the robot snapshots being missing because the "Now" timestamp is fixed

Revise Predictive: Split into Predictive (base, no children) and PredictiveContainer (with children)

Make ProviderSegment a Predictive, others a PredictiveContainer.
Remove non-const ref access to underlying container

Turns out std::stringstreams can't be copied, so you can't use them in
containers.