ControlStrategyMitigates.csv deprecated

[mike1813]

The 'mitigates' relationship from a ControlStrategy to a Threat previously specified that the ControlStrategy blocks a threat only for the purposes of a FUTURE risk calculation. This has been deprecated since the introduction of separate boolean properties for Threats and ControlStrategies, specifying whether they are applicable to CURRENT or FUTURE risk calculations.

The table ControlStrategyMitigates.csv has for some time been an empty table, containing only a header row and a dummy row providing a long text field to ensure that when imported into the MS Access DB editor, subsequent rows are not truncated to a short text object.

If the flag HAS_RISK_TYPE_FLAGS is present in the DomainFeatures.csv table, it is reasonable to assume that ControlStrategyMitigates.csv is empty, so reading that file could be skipped. However, csv2nq.py still does read the file, presumably because at first some domain models may have retained an old 'mitigates' relationship instead of using the boolean risk-type properties. In new domain models the table ControlStrategyMitigates.csv no longer exists, causing csv2nq.py to crash when the input file cannot be found.

This should be fixed. For backward compatibility, csv2nq.py should still read and translate this file, but only if the flag HAS_RISK_TYPE_FLAGS is not present in DomainFeatures.csv.