Add option to have camera blend between two settings based off player distance

[Majora-OX]

Adds an additional checkbox to camera triggers to blend by distance. If enabled, when the trigger is activated the camera will switch/blend to the set camera settings as normal. But it will then continue to blend between the first setting and a second given setting based off players distance from a Vector3 point instead of time.

The point is set like Drift Triggers points, and is made viewable in the editor as well.

At least one camera angle in BK requires this, but I'd imagine this option could be usefull in parts of SR as well. (Looking at footage of Night Palace it seems to do this in the starting side view section)

[Kuma-Boo]

Thanks for the heads up! We'll definitely need proper distance blending.

I tried your branch and have the following notes:

• There were some merge conflicts with the dev branch :(
• There are some unnecessary parameters being passed to the CameraController.
• Using a linear distance would cause issues whenever the level restricts Sonic to a curved path instead of a straight line.
• The code doesn't follow the project's coding style in some areas.

The core implementation of the idea is solid though, so I tried recreating it in #256. Maybe we could use that instead.