Add way of knowing what platform the endpoint request is coming from.

[jonedmiston]

Description

In the future Helix could be used from multiple platforms (web/mobile/etc). It would be nice is there was a common way of knowing the platform from inside of the endpoint so the logic could respond with the appropriate markup.

Actual Behavior

Everything is assumed to be web.

Expected Behavior

Some new merge field would describe the requests platform.

Steps to Reproduce

na

Issue Confirmation

• Perform a search on the Github Issues to see if your bug or enhancement is already reported.
• Try to reproduce the problem on a fresh install or on the demo site.

Rock Version

v16.x