Add login action for Redux

Add LoadingSpinner component

Add productUpdate action for Redux

Add createProduct action for Redux

Add deleteProduct action

Add productDetail reducer

Add redux toolkit and base productList reducer

Add ProductUpdate component

Update input and select text color for placeholder

Add category selection to ProductForm

Add InputFiltering component and integrate it into ProductList

Merge pull request #18 from Gamattowicz/backend

Update test_product mock for create_thumbnail

Move creating a product image to a separate function and add update_product endpoint

Add SelectSorting component