PayPal Provider

[0vol]

Description

Added implementation of a payment provider service using Paypal's Checkout Server SDK.

• ProviderService Class: extends an abstract service and implements a payment interface. It has two main methods: createACheckoutSession and checkRequestAndReturnDetails.

• createACheckoutSession Method: creates a new checkout session for a transaction, sets up the details of the transaction, such as the amount and currency, and then sends a request to PayPal to create a new order. If successful, it returns the order ID.

• checkRequestAndReturnDetails Method: This method takes a request (which should contain an order ID) and sends a request to PayPal to get the details of that order. If successful, it returns the order details.

• client Function: a helper function that creates and returns a new instance of PayPalHttpClient.

---

Issue Ticket Number

Fixes #4

---

Type of change

• [ ] Bug fix
• [x] New Provider
• [ ] Styling
• [ ] New Feature

---

Checklist:

• [x] I have checked to ensure there aren't other open Pull Requests for the same update/change?
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes needed to the documentation