(optional) The options for loading. Options are:
customLoadingText [type: String] - (optional) Custom loading text to show. If this is null, default text is used.
element [type: HTMLElement] - (optional) The element to show the loading overlay on.
cancelCallback [type: Function] - (optional) The function to call if the user cancels this loading. This only works if 'element' is supplied.
showDelay [type: Number] - (optional) Time delay in milliseconds before showing the loading screen, defaults to 500ms if null.
isInputInlineLoading [type: Boolean] - (optional) Specifies the loading should be an inline input loading icon. If this is used, element must be specified (the input element).