Add gamerule: minecart_air_resistance

After experimenting with the experimental minecart improvements, I feel a useful tool would be the ability to control air resistance constants in addition to other constants that affect the speed of minecarts. This idea came when I was trying to find a way to make minecarts more viable as transportation compared to something like an elytra, but without making minecarts way too fast with only like 6 powered rails. I wanted a way to increase air resistance and friction constants so I could make sure it took more effort to get a minecart to be that fast, for example simply doubling the max speed was almost too fast too quick, but would be perfect if resistance factors were stronger so you still have to put effort into making a fast minecart but this form of land travel is still faster than air travel with elytra if you put in the effort to create it. A creative way to balance the two modes of transport with each other. Adding gamerules like this or a way to easily interface with these constants also gives the player much more creative freedom when creating servers, experiences, etc, using the new experimental features.