Rename the frog chassis to “The bullfrog”

The new chassis coming to EA2 is so far known as “the frog chassis,” with the nickname of the seafrog. From lore, we know the frog chassis isn’t fully designed to be used underwater, and overall it’s a heavy duty mech walker. So, why not call it the Bullfrog? A large, heavy, and strong frog, just like the frog chassis.