rtmp-services: Add Frontro as a service

[Fyb3roptik]

Description

Adds Frontro (www.frontro.com) as an RTMP service

Motivation and Context

This is a feature for adding Frontro as an RTMP service

How Has This Been Tested?

I built and tested this with the Frontro service and it does work

Types of changes

Simply added the service to services.json

Checklist:

• [x ] My code has been run through clang-format.
• [x ] I have read the contributing document.
• [x ] My code is not on the master branch.
• [ x] The code has been tested.
• [ x] All commit messages are properly formatted and commits squashed where appropriate.
• [ x] I have included updates to all appropriate documentation.