Bring java shields to bedrock edition

Bedrock should ditch the crouching system for shields and make rightclicking the new way to pull up your shield like in java. also allow the f key to swap thee item in your main hand and your off-hand. these are just small steps to further the abilities of the bedrock offhand. i hope that eventually, we will also be able to put any item in the bedrock offhand, and maybe even one day bring the java attack cooldowns and axe damages to bedrock addition to bring the 2 versions closer