[Accessibility] Toggle Block Breaking Behavior Semi/Full Auto Modes

Add a bindable toggle command that swaps between two block breaking modes; Semi Auto and Full Auto. Full Auto is what we have now; holding down the mouse button will continue to break blocks as long as it's held, as fast as they can be broken. Semi Auto only breaks one block per mouse press, no matter how long the button is held or where you turn to look. To aid with visibility, there would probably be a indicator icon somewhere on the screen that pops up and fades away to indicate that you have changed modes (something like a pick hitting a block with an infinity symbol vs a pick hitting a block with a ×1, kind of like the attack cooldown indicator).

This would mainly help players who have difficulty with motor control break individual blocks that can be insta-mined without using external programs or mouse macros. It would also benefit players who are doing repetitive building tasks that require breaking just one block at a time without harming the surrounding blocks in a build.

Some tangible examples of this feature would be collecting snow off of a dirt surface; hit the key bound to the toggle to switch from Full Auto to Semi Auto and you can harvest each snow square without accidentally breaking the dirt underneath. Another example would manually harvesting Amethyst crystals from a geode; as long as you are aiming at the Crystal's hitbox first, you won't have to worry about damaging the irreplaceable node block behind or adjacent to it.