This change makes is so that when a time-picking modal (e.g. "Add bookmark" modal) is visible, **all** global key bindings are paused.
1. Fixes an issue where opening and closing a time-picking modal would break global single-key keybinds, so for example, <kbd>L</kbd> would no longer like posts, but <kbd>L</kbd> <kbd>L</kbd> would
2. Fixes a related issue, where doing the above would also override custom keybinds provided by plugins (e.g. <kbd>L</kbd> shortcut that discourse-reactions uses)
Included:
* DEV: Reset Mousetraps instead of unbinding
* FIX: Make unbind use unbind
* DEV: Don't check for keyTrapper twice
* DEV: Use an instance of Mousetrap
* DEV: Remove an invalid `for` attribute (`set_reminder` doesn't exist)
* DEV: Add ability to pause all KeyboardShortcuts
* FIX: Pause all keybinds when in a time-picking modal
* DEV: Move bookmark keybind resets to willDestroyElement
* DEV: Fix shortcuts-related tests
Using arrow functions changes `this` context, which is undesired in tests, e.g. it makes it impossible to setup things like pretender (`this.server`) in `beforeEach` hooks.
Ember guides always use classic functions in examples (e.g. https://guides.emberjs.com/release/testing/test-types/), and that's what it uses in its own test suite, as do various addons and ember apps.
It was also already used in Discourse where `this` was required. Moving forward, it will be needed in more places as we migrate toward ember-cli.
(I might later add a custom rule to eslint-discourse-ember to enforce this)
We used many global functions to handle tests when they should be
imported like other libraries in our application. This also gets us
closer to the way Ember CLI prefers our tests to be laid out.
This is where they should be as far as ember is concerned. Note this is
a huge commit and we should be really careful everything continues to
work properly.
