Adds new `max-egg-stack-size` option for chicken stacks

[heypr]

As stated in the title, this PR adds in a max-egg-stack-size option for chicken entity stacks.

This does not fix an open GitHub issue, and instead fixes an issue where chicken entity stacks would drop eggs equaling their current stack size, i.e. a chicken stack with three billion chickens would drop 3 billion eggs.

I set the default value for this option to 10,000, let me know if that's too low or too high.