KCheckbox had local data which are initialized to the given props for
    `indeterminate` and `checked` and then updated in a watcher. This
    resulted in that clicking a checkbox would always toggle it's
    `isCurrentlyChecked` value and setting `isCurrentlyIndeterminate` to
    false.

    The changes here instead have KCheckbox simply use the given prop values
    and does nothing to manage any internal state around whether it shows
    `indeterminate` and/or `checked`.

    This results in users of KCheckbox needing to be mindful of how they
    manage the values they pass into KCheckbox's props as the component will
    now reflect their values at all time