Revamp the Ballerina Stripe connector

[ayeshLK]

Description:

$subject

As an internal support issue [1] we got a requirement to improve our existing Stripe connector to support several APIs such as PaymentIntent, Refunds, and Charges etc. As our current Stripe connector does not have the support for the latest APIs which is provided by Stripe we need to revamp the existing Stripe connector.

Following tasks should be completed with this effort:

• [x] Sanitize the Stripe provided OpenAPI spec and generate the client connector
• [x] Add mock tests for the Stripe connector
• [x] Improve the documentation with setup guide and quickstart guide
• [x] Add example usecase for the Stripe connector

[1] - https://github.com/wso2-enterprise/internal-support-ballerina/issues/719

[ayeshLK]

Closing this issue as all the relevant tasks are completed.