fixes eventToHotkeyString returns doubled "modifier" when "key" is a modifier

[theinterned]

resolves #60

This PR fixes a bug where eventToHotkeyString was returning a "double modifier" for a key-combination where a modifier key (Control, Alt, Meta, or Shift) is also the event.key.

This PR updates eventToHotkeyString so that the resulting string still presents modifiers in a consistent order.

For more details see #60

Before	After

Screencast of the after

Screen.Recording.2021-12-16.at.5.59.41.PM.mov

Breaking change

Although the previous behaviour was likely a bug, this is a breaking change in that it changes the "hotkey string" format when a modifier key is used as the hotkey (the final element in a hotkey string sequence) for example Meta+Shift+Shift becomes Meta+Shift after this change.

[theinterned]

These were initially failing with:

FAILED TESTS:
  hotkey
    eventToHotkeyString
      ✖ {"ctrlKey":true,"shiftKey":true,"key":"Shift"} => Control+Shift
        Chrome Headless 96.0.4664.110 (Mac OS 10.15.7)
      Error: Uncaught AssertionError: expected 'Control+Shift+Shift' to equal 'Control+Shift' (node_modules/chai/chai.js:250)
          at Context.<anonymous> (test/test.js:232:23)

      ✖ {"ctrlKey":true,"shiftKey":true,"key":"Control"} => Control+Shift
        Chrome Headless 96.0.4664.110 (Mac OS 10.15.7)
      Error: Uncaught AssertionError: expected 'Control+Shift+Control' to equal 'Control+Shift' (node_modules/chai/chai.js:250)
          at Context.<anonymous> (test/test.js:232:23)

[theinterned]

I wonder if you reviewers would consider this a breaking change? It is arguably as the format of the string does change.

[keithamus]

This looks good 👍

I do think it's a breaking change. Maybe we should rip the band-aid off with a breaking change that reworks the format?