Improve module imports

[rrickgauer]

• make a new package called routes
• take all the controllers.py code and make a new module for each one
• in the routes __int__.py file, import each of the route sub-modules
• update the api_wmiys __init__.py to use the new route sub-modules
• rename all files to have a lower case name
• for all the route packages that have a related class, move all the classes to a new package called models
• modify all absolute import statements into relative import statements
• rename all blueprint variables to follow the same naming convention: bp_resource_name

[rrickgauer]

routes' sub-modules:

• locations
• login
• product_availability
• product_categories
• product_images
• product_listings
• products
• search
• search_products
• users

[rrickgauer]

Common.Sorting.py

• Rename the file to sorting.py
• Create a sorting type enum (asc or desc)

[rrickgauer]

Pagination.py

• Fix up the class
• rename file to pagination.py

[rrickgauer]

Utilities.py

• migrate all the static methods to functions (no class)
• rename the file to utilities.py