Fixes #4275 & #413

This PR adds several camera modes for modifying FOV:

• aiming – aiming with a weapon

• sniper_aiming – aiming with a sniper rifle (with increased zoom range)

• 1stperson_aiming – aiming with a weapon using the flag_aim_1st_person

• vehicle_bump – bumper camera view in vehicles

This PR also adds a resetCameraFieldOfView function to restore default values.

Important notes:

• The aiming, sniper_aiming, and 1stperson_aiming modes should be used within the render loop, as their FOV values are overwritten every frame.

• resetCameraFieldOfView does not reset the FOV for the aiming mode while actively aiming. The FOV will automatically reset once the player stops aiming.

• Low values, as documented on the wiki, may cause visual glitches but do not cause crashes (tested).

• Using setCameraFieldOfView with the sniper_aiming mode increases the sniper zoom range from the default to the full function range of 0–179. This extended range remains until resetCameraFieldOfView is called, which then restores the default range of 15–70."

Thanks to @sacr1ficez for the ideas and testing.