Support different product sizes

[lemeryfertitta]

For a given product there can be multiple sizes. For example, the "Kilter Board Original" product (ID = 1) has the following sizes:

• 8 x 12
• 7 x 10
• 12 x 14
• 12 x 12 with kickboard
• 12 x 12 without kickboard
• 16 x 12

For a given product size:

• The image of the board should be the
• The list of climbs should be limited to holds that are within the bounds of the product size