Extract logic to NoteDataUtil::StringInterpretsAs

src/NoteDataUtil.h

@@ -23,6 +23,11 @@ void LightTransformHelper( const NoteData &in, NoteData &out, const vector<int>
  * and makes it much easier to change NoteData internally in the future. */
 namespace NoteDataUtil
 {
+	/**
+	 * @brief Whether a string can be interpreted as the provided signed integer
+	 */
+	bool StringInterpretsAs( const std::string& str, int integer );
+
 	NoteType GetSmallestNoteTypeForMeasure( const NoteData &nd, int iMeasureIndex );
 	NoteType GetSmallestNoteTypeInRange( const NoteData &nd, int iStartIndex, int iEndIndex );
 	void LoadFromSMNoteDataString( NoteData &out, const RString &sSMNoteData, bool bComposite );