Refactor & simplify InputHandler.ts

[evanpelle]

Refactor it into a "binding" system to simplify mapping of key => action.

example:

{
  inputs: [ Keyboard.ButtonDown('A') ],
  event: {
    type: FooBarGameEvent,
    factory: (manager, input, binding) => new FooBarGameEvent(input.value),
  },
  labelKey: 'user_setting.foobar',
  descriptionKey: 'user_setting.foobar_desc',
  isEnabled: false,
  isConfigurable: true,
}

Discord thread: https://discord.com/channels/1359946986937258015/1456342312668893308

[bosconian-dynamics]

Implementation may affect the following issues:

• keyboard shortcuts: use code for detection and key for display #1071
• Buttons for faster Structure and bomb placements on mobile devices #2590
• Cannot rebind some zoom keys #2292
• Bug: New build keybinds reset after update site or start game #2209
• [CONTROLS] More key bindings, improved building menu #1217
• Keybinds - Unbind key button doesn't work #2291
• Keybinde Overlapping and rebinding issue #2652