Rewrite product attribute values to provide additional context to better match how people search

For the same reason it is important to rewrite website category names, in many instances, the attributes that have been selected for the product title prefix need to be overriden. This can also be done in the FeedOps interface.

For example, many websites have the size attribute as S, M, L, etc. Again, this has context within the website, but should be expanded in the product title. This ensures that if someone is searching for a "small men's shirt", the relevant products are shown.