Add new functions related to underwater effects

[XJMLN]

Client functions

• setCameraUnderwaterEffectEnabled(bool state) - Enable or disable the underwater effect. This function does not affect the default diving behavior.
• setCameraUnderwaterEffectSpeed(float speed, float frequency) - Change the speed and frequency of the underwater effect
• setCameraUnderwaterDarkness(bool state, float maxDarknessDepth) - Enable or disable the screen getting darker as we dive deeper underwater. We can also set the depth at which the screen goes completely dark.
• getCameraUnderwaterEffect() -> bool enabled, float speed, float frequency
• getCameraUnderwaterDarkness() -> bool enabled, float maxDarknessDepth
• resetCameraUnderwaterEffect() - Reset the underwater effect state, speed and frequency to their default values
• resetCameraUnderwaterDarkness() - Reset the underwater darkness effect state and maximum darkness depth to their default values

Resolves #1297

[Proxy-99]

Great! We can fix #2598 by checking if the underwater effect is on, maybe after this PR merged?

[XJMLN]

Currently, getCameraUnderwaterEffect will return true only if it was enabled by setCameraUnderwaterEffectEnabled. I don't know if this is valid; maybe I should additionally check the value of CWeather::UnderWaterness(0xC8132C), which is used to enable this effect and changing the weather to ID 20 while underwater. Then getCameraUnderwaterEffect would return true in that case.

[Proxy-99]

Currently, getCameraUnderwaterEffect will return true only if it was enabled by setCameraUnderwaterEffectEnabled. I don't know if this is valid; maybe I should additionally check the value of CWeather::UnderWaterness(0xC8132C), which is used to enable this effect and changing the weather to ID 20 while underwater. Then getCameraUnderwaterEffect would return true in that case.

I think we should be able to check the effect anytime without relying on setCameraUnderwaterEffectEnabled

[Proxy-99]

resetCameraUnderwaterEffect() should not this also reset darkness too

and getCameraUnderwaterEffect() should not also get the darkness level too
instead of calling another function to check

[TheNormalnij]

Nice job!
Reset effects when a player connect to a new server. please