Change to DataAbsentReason = does not exist for mustHave

[juliangruendner]

IS:

Currently a DataAbsentReason is considered as a field / attribute existing
when mustHave is calculated

SHOULD:

If a field has a DataAbsentReason it should be consided as NOT EXISTING
for the mustHave calculation.

[juliangruendner]

@alexanderkiel , @paulolaup , @kleinertp - do you agree with this?

[Lucas0T]

Depends what must have means in the end.
I can live with both "field is filled with information including why information is not there" and
"DAR count as missing".

[paulolaup]

There might be some absent reason codes that indicate that data is available and just not accessible via this route. We should should consider treatment based on these code values.

[juliangruendner]

There might be some absent reason codes that indicate that data is available and just not accessible via this route. We should should consider treatment based on these code values.

but is this relevant in our case - do we care why something is not available - if it is not available to torch?