CameraFrame API in the engine

[mvaligursky]

Fixes https://github.com/playcanvas/engine/pull/7129 (separate improvements / changes can be tracked separately)

This adds a new CameraFrame class as part of the engine, which is a public API for the currently exposed render pass based rendering. The script which exposes this to the Editor now uses an instance of this CameraFrame, and simply passes attributes to it, without containing any logic. This allows it to not access any private engine functionality.

This is the new public API (too long to copy here) https://github.com/playcanvas/engine/blob/mc-engine-camera-frame/src/extras/render-passes/camera-frame.js

• also updated engine examples to use CameraFrame module directly, without using the script.
• updated eslint config to ignore some custom tags we added to MJS scripts

[mvaligursky]

I'll merge this for now, further feedback / changes will be address by a follow up PR @willeastcott