feat(movement): add WaterSpeed as a TerrainSpeed mode

[minecrrrr]

This PR introduces a new WaterSpeed module, designed for servers without anti-cheat checks (vanilla gameplay).

Key features:

Vanilla Only: The module is intended for vanilla movement physics and does not contain anti-cheat bypasses. Only the Vanilla mode is available.
Auto Swimming: Automatically enables swimming mode when the player touches water.
Speed: Adjusts movement speed when in water but not in the full swimming state (e.g., treading water on the surface).
SwimmingBoost: Provides an additional speed boost when in the swimming state.

This adds new functionality to the client for movement in water environments.

Config:

[6x68]

couldn't you technically classify water as terrain, so then it should be moved into terrain speed?

[minecrrrr]

Technically, that makes sense