Add book lookup functionality to book sponsorship page

Add javascript to the sponsorship page book lookup/search:

We'll probably want to let them search by
1) ISBN
2) Amazon url or ID (which means we may have to extract ID from the amazon URL
3) Open Library url or ID (again, will have to be able to extract edition or work ID from url if necessary)

If we're given an amazon ID or ISBN, we'll use the `https://openlibrary.org/isbn/{ID}` API to discover the corresponding Open Library item and return the book data back to your front-end.

If the user gives an Open Library ID (work/edition) and there's no ISBN, we'll say it's not eligible (and not explain why, there are too many reasons this could be and it's better not to confuse the patron). If there is an ISBN, we can use this also to fetch the price from Better World Books + Amazon via Open Library's price API:

`https://openlibrary.org/prices?isbn={isbn}`