Circular dependency detection: Outputs which are pogrammatically set to faulty are treated like external inputs.

After discussion with Martin K. we concluded that this monitor makes no sense. Legit cases should use the ExactMonitor
instead (if e.g. a boolean on/off configuration switch is to be observed). The monitoring of a Status value makes
no sense, since we would then have a monitor monitoring another monitor. In that case, the behaviour of the other
monitor should either be corrected, or the monitors should be aggregated with the right aggregator mode.

- introduce StatusOutput class
- rename ChimeraTK::States enum to ChimeraTK::StatusOutput::Status and make strongly-typed
- introduce reserved tags to detect StatusOutputs to be aggregated

* Not implemented yet. Currently always return false.
* Test exists and compiles, but is failing due to the missing implementation.

This is changed behaviour introduced with c9948142

Before it had to be stripped for all use cases anyway, so it is better to leave it out from the beginning.

For some reason this was disallowed and even tested to throw.

This actually makes the implementation also easier and more efficient.

* add HierarchyModifyingGroup

* VirtualModule: allow nested oneLevelUp etc.; simplify implementation

This is achieved by properly setting the _owner of each VirtualModule (unless highest level).

The simplification comes from then being able to use getOwner() instead of keeping track of "grandparents", and from using createAndGetSubmodule() instead of implementing something similar again in findTagAndAppendToModule().

* DataLossCounter constructor now takes qualified path to trigger variable

Co-authored-by: Jens Georg <jens.georg@desy.de>

Forgot to adpopt test to the new method signature.

* Fix initial msg. Add automatic connection to the LoggingModule.

Now the Logger is a VariableGroup and in the prepare() method an empty
msg is written once. This makes sure the LoggingModule is not waiting
for initial values of Loggers and messages by other Loggers get lost.

* Add message in case on modules with Logger are found.

* Fix test and remove implementation of removed method.

* Do not use hard coded tags but use default tags.

Now all tags given to the LoggingModule are used to look for senders.

finally managed to cook up a test that is sensitive to the connection errors when using hierarchy modifiers

This closes #29.

Manual check to be used temporarily.

These additions cover the behavior described in #29.