derivedDataType NumAnaString2to007DT

EcimDerivedString with length (2..7) constraint.
Should really be using (2..5) but we have to use this higher limit becuase of COM is counting the + sign as \2B and think the value is 3 character long :(

References from:: NumAnaCountryCallType;

string NumAnaString2to007DT [ 2..7 ]
Valid values: ^(\+|\\(\+|(2[Bb])))[0-9]{1,4}