feat(enhancement): Dynamic Camera Acceleration

[Koranir]

like #7347, but better >:)

Adds an optional camera acceleration to the game, to make the player feel more dynamic. Can be reversed to make the camera go ahead of the player as well. The camera's values are up to change if need be, I'm using some insane engines & afterburners in the video to fully demonstrate the feature though.

https://github.com/endless-sky/endless-sky/assets/101683475/4ed9be58-b48a-4ccf-802a-6abbd8e9a28c

First PR of the year, <40min in >:)

Tested with all the UI elements enabled, no desyncing.

[RisingLeaf]

We only want use NewCenter when the setting is not off

[Koranir]

We only want use NewCenter when the setting is not off

If the setting is off, the offset multiplier is zero anyways and the center will stay at the flagship's position. No need to do another check.

[RisingLeaf]

We only want use NewCenter when the setting is not off

If the setting is off, the offset multiplier is zero anyways and the center will stay at the flagship's position.

ye but we dont need to do the calculation

[Koranir]

The effect is subtle enough in regular gameplay and adds a lot to the game feel that I think it should default to on. I've playtested it with ye olde marauder leviathan and it's very non-intrusive.