rename categoryService to categoryService
make test useable
add test isIncludeProduct
add test loadAllCategories
add test insert
add teset delete
add test getCategoryByid
add test loadAllCateogries
make test useable
add test loadAllProducts
add test getPagetTotal
add test getPagetTotal
add test getPrevious
add test getNext
add test delete
add test updateProduct
remove useless function
add test insert
add test addToCart
remove useless test