Added Serverless Endpoint Class

[ipalvr]

Description

I have a customer who is automating serverless vulnerability reporting and they would like to leverage a script like the one we have for hosts. Here is the path to the hosts example. prismacloud-api-python/prismacloud/api/cwpp/_hosts.py

Motivation and Context

Addition of serverless vulnerability reporting

How Has This Been Tested?

I worked with the customer to test.

Screenshots (if appropriate)

N\A

Types of changes

• New feature (non-breaking change which adds functionality)

Checklist

• [x ] I have updated the documentation accordingly.
• [ x] I have read the CONTRIBUTING document.
• [x ] I have added tests to cover my changes if appropriate.
• [ x] All new and existing tests passed.