[Forwardport] Added checks to see if the payment is available

[gelanivishal]

Original Pull Request

#15683

Fix an error while submitting an order without payment method.

Description

When submitting an order using the rest api without an payment, you would get an exception/error report due to the fact there was not payment method.

Fixed Issues (if relevant)

1. REST API create order POST /V1/orders #15652: REST API create order POST /V1/orders

Manual testing scenarios

1. Send an POST request to the rest/V1/orders endpoint containing the following:
   { "entity": { "base_grand_total" : 100, "customer_email" : "user@domain.tld", "grand_total" : 100, "items" : [ { "sku" : "TESTSEB" } ] } }

Contribution checklist

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds on Travis CI are green)

[sidolov]

Hi @gelanivishal , please, add following commit to this port: 7bc5df7
Thank you!

[gelanivishal]

@sidolov Added.

[magento-engcom-team]

Hi @sidolov, thank you for the review.
ENGCOM-3156 has been created to process this Pull Request

[magento-engcom-team]

Hi @gelanivishal. Thank you for your contribution.
We will aim to release these changes as part of 2.3.1.
Please check the release notes for final confirmation.