refs https://github.com/TryGhost/Team/issues/993
- added calls to `onFocus()` and `onBlur()` arguments inside the trigger when the input is focused/blurred so that the active class is correctly applied by ember-power-select
- removed unnecessary mousedown propagation cancellation, it was a copied from `<GhTokenInput>` where extra mouse handling is necessary for buttons inside tokens
- updated `.gh-input-with-select` styles to add the border when active
refs https://github.com/TryGhost/Team/issues/987
- `<GhInputWithSelect>` acts as a typical text input element but will also show options that are filtered whilst typing. Useful for inputs where there should be suggestions or the ability to choose an existing option
- updated `<GhSearchInput>` to use the renamed and slightly modified trigger