Enable limiting max melody range for a question in scale degree exercise

[ShacharHarshuv]

For example if limiting by 3rd then "Do-Mi-Re" is OK (range is a 3rd) but "Do-Mi-Fa" is not.

Options should be:

• 3rd
• 4th
• 5th
• 6th
• 7th
• 8th (default)
• No limit