Add Phantom Camera addon

[manuq]

https://phantom-camera.dev/ seems generic enough, and would make it very easy to:

• Transition from framing the player to frame another object, while describing it (eg. "this is the jar you need to fill")
• Frame a group of entities.
• And much more.

After discussing briefly with @wjt the pros/cons of using an addon for camera, we think that this one is worth it.

[manuq]

This can also replace scenes/game_logic/camera_behaviors/frame_camera_behavior.gd.

What that script tries to do is: When the player grapples, the camera follows the tip of the string. But only if that point is at the margins of the camera frame (close to the screen border). Otherwise, the camera starts following the string immediately as the grapple is triggered, making multiple throws to the air very shaky.

Phantom Camera can do this easily.

[wjt]

Some more uses-cases for a fancier camera, some of which could probably be accomplished with what we already have & a little bit of custom logic:

1. Adjust the camera margins/offset during dialogue so that the player/npc are not obscured by the balloon
2. Frame the Eternal Loom in all its majesty when you are within some range of it

[manuq]

This could also help with #1853