Hammer Keybind Editor improvements

[HugoBDesigner]

1. When two keybinds are set to the same shortcut, the warning window has an improperly labeled confirmation button (that also cannot be pressed). The only way to exit the window is by pressing escape:

2. After making a change to a given shortcut, it does not update the listed shortcut in the user interface, even after a restart:

3. There is currently no way (at least none presented clearly to the user) to actually remove a keybind shortcut. If a given action starts out with a preset shortcut, the only option given to the user is to change it to a more difficult/unusual shortcut;
4. Not a bug, but it would be appreciated if users could search through the binding list for a specific action, as well as search for specific existing keybinds. This would also require all bindable actions to have written descriptions that could also be searched through. Most software that provide a comprehensive and flexible bindings system seem to include some form of search bar. Pictured: Notepad++