Add setting to control how integrity service acts in case of information collection failure

Integrity service will, if a contributor fails, ignore the fact and continue as nothing had happened with its checks on a incomplete set of data.
The handling should be changed, so that it will do:
1) abort the integrity check and throw an alarm telling why it's being aborted
2) or continue the checks, but not clean any state (only relevant for the full check), and notify by alarm that the check is not based on a complete set of data.