fix(payments_create): save the customer_id in payments create

[Narayanbhat166]

Type of Change

• Bugfix

Description

In case we receive a 4xx when creating the payment before calling the connector, we do not save the customer_id in payment intent. This PR fixes it

This PR also includes changes to ensure that customer_id is always taken from both the places in the PaymentsRequest. The root customer_id and customer.id field.

Motivation and Context

How did you test it?

• Create a merchant account

curl --location 'http://localhost:8080/accounts' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'api-key: test_admin' \
--data '{
    "merchant_id": "merchant_1720593206"
}'

• Create an api key

curl --location 'http://localhost:8080/api_keys/merchant_1720593134' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'api-key: test_admin' \
--data '{
  "name": "API Key 1",
  "description": null,
  "expiration": "2038-01-19T03:14:08.000Z"
}'

• Create a payment

curl --location 'http://localhost:8080/payments' \
--header 'Content-Type: application/json' \
--header 'Accept: application/json' \
--header 'api-key: dev_RMV9h1z6QVqWHW9B7LBRl6peSokwQ7go96pfAjehuGZDGiwlenKAbgtyqUlXny9J' \
--data '{
    "amount": 0,
    "payment_id": "pay_1720593248",
    "customer_id": "cus_123",
    "currency": "USD",
    "confirm": true,
    "payment_type": "setup_mandate",
    "payment_method": "card",
    "payment_method_data": {
        "card": {
            "card_number": "4111111111111111",
            "card_exp_month": "10",
            "card_exp_year": "25",
            "card_holder_name": "joseph Doe",
            "card_cvc": "123"
        }
    }
}'

Fails with the error message

{
    "error": {
        "type": "invalid_request",
        "message": "No eligible connector was found for the current payment method configuration",
        "code": "HE_04"
    }
}

• Check in the database whether customer_id is updated

Checklist

• I formatted the code cargo +nightly fmt --all
• I addressed lints thrown by cargo clippy
• I reviewed the submitted code