While loading, the entire dropdown is greyed out. However, The focus is on the text input, so user can input text. Move the focus event to after loading finished to fix this.

CoffeeScript generated JavaScript contains some unreadable
expressions. This refactoring addresses complex uses of
the exestential operator that produced unreadable Javascript.

- Fixes an issue where `renderItem` is called several times even when
  not required
- Increased performance when rendering dropdown items

Closes #21110

Stop the global search form's default "action" from fighting with
dropdown items when using the keyboard to navigate the dropdown.
`e.preventDefault()` is now called on the enter key when a dropdown item
is already selected.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Replace single quotes with escaped single quotes and write spec to test multiple lable selection over a page load

Added spec for removing label with space and single quote

Fixed removing label with single quote

Restore changes introduced in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/581

Completed project filter dropdown, still need to move it from inline to ProjectSelect.js (or different)

Closes #15552

Moved `.option-hidden` to exist only in `SELECTABLE_CLASSES` as `NON_SELECTABLE_CLASSES` is used to re-show previously hidden elements

Closes #20627

We should stop passing events as a parameter since we cannot call the method programatically without faking or creating an event even when that event is not entirely required.