Refactor API-Wrapper.js

[rrickgauer]

• remove callback methods and use promises instead
  • ensure that each method is being used, if not delete it
• break down the class into smaller child classes
• Create a standardized way to turn a native JavaScript objects into a FormData or URLSearchParams object

[rrickgauer]

API Wrapper Routines With Callbacks

• [x] requestPostUser
• [x] requestLogin
• [x] requestPutUser
• [x] requestGetProductCategories
• [x] requestGetProductCategoriesMajor
• [x] requestGetProductCategoriesMinor
• [x] requestGetProductCategoriesSub
• [x] requestPostProduct
• [x] requestPutProduct
• [x] requestGetUserProducts
• [x] requestGetProductAvailability
• [x] requestDeleteProductAvailability
• [x] requestPostProductAvailability
• [x] requestGetProductImages
• [x] requestPostProductImages
• [x] requestDeleteProductImages
• [x] requestGetLocation
• [x] requestGetProductListingAvailability