Adds an menu item in "Settings" to toggle the HUD shield/bubble button on or off.
Shield button remains available in the tablet or toolbar, it is called "HUD shield button" but suggestions are welcome
fixes https://github.com/vircadia/vircadia/issues/1210
Now uses separate images for each state. Now tabletButtonProxy has 4 state properties, one for icon and images.
* icon
* hoverIcon
* activeIcon
* activeHoverIcon
* text
* hoverText
* activeText
* activeHoverText
Updated scripts to set new button states, if necessary.
This height allows my friends to stay in my view comfortably, even when the space bubble is on. Even though it's significantly lower, I don't think anyone is not going to look down when someone starts to shrink down in front of them.
* The space bubble around a player's avatar is now visualized. When another avatar enters a player's bubble, The bubble visualization will appear, a soft tone will play, and the "Bubble" HUD button will flash.
* The space bubble radius setting has been removed. Space bubble size now scales based on avatar scale.
* Space bubble collision detection is now more accurate and reliable.
* CTRL + N toggles the bubble.
* The "Bubble" HUD button has been moved to the proper location.
