Paypal integration

[ptmaroct]

We need to integrate paypal for taking payments.
Currently we have paypal payment buttons which are just external pages which accept payment and send a webhook.

The endgoal is to capture email of who paid and increment their available_ships count in the user_profiles table in supabase.

[ptmaroct]

We already have the frontend integrated, need webhook handling in server.js only

Similar logic is already written for Razorpay webhook