Fix leash interaction bugs

Currently, there is a bug where if you right click a fence with a certain item it glitches. This due to the fact leashes allow the player to interact with fences, even though they don't need to hold a leash. This patch fixes it by checking their held item, and if it is one that causes a glitch, then end it there instead of going on to start the glitch. It also checks if the player has a leash attached to them to make sure that it won't cancel the leash being attached when they interact a fence. I had good results after testing this several times on my local, but feel free to test it out to find any potential bugs that could arise from this. While testing, I attempted to re-create 1.7.10 behavior, and it seems to be functioning properly so far. Thanks.