REQUEST METHOD - MYSQL PROCEDURE NAME - ARGUMENTS
functions' arguments (& their names) are matching with mysql procedures' arguments. (except api/food)
######## api/order
- GET select_all_order - args: none
- POST create_orderWithCustomer - args: 11pcs
- POST create_order_food - args: 3pcs
- POST set_orderStatus - args: 2pc
- DELETE delete_order - args: 1pc
######## api/food
- GET select_all_{food} - args: 1pc -> food_group_id (1=pizza;2=hamburger;3=gyros)
this will return the image in a base64 encoded string
######## api/address
- GET getAddress - args: none
######## api/admin
- POST set_admin - args: 2pcs
- GET none - args: none - GET request will return all username/password (TEMPORARY)
