Search products, offline mode, bug fixes

• Search products
• Infinite scroll for categories & products list
• Cache content with redux-persist (offline mode)
• Disable product slider when images are not cached (offline mode)
• Open product or category details at image tap
• Upgrade dependencies from package.json to latest versions
• Bug fix - shop name not wrapping in the top bar
• Bug fix - cart products maintain their order when quantity is edited
• Bug fix - cart total (sum)
• Bug fix - prices displayed in the cart are rounded to two decimals