Refactored the initial getResOperandValue() to getResOperandSegmentValue(); a common logic method returning a SegmentValue
Created getResOperandValue() (resp. getResOperandRelocatable()) which calls getResOperandSegmentValue() and enforce the returned value to be a Felt (resp. a Relocatable).
Closes #129
getResOperandValue()togetResOperandSegmentValue(); a common logic method returning aSegmentValuegetResOperandValue()(resp.getResOperandRelocatable()) which callsgetResOperandSegmentValue()and enforce the returned value to be aFelt(resp. aRelocatable).