Make modals programatically controllable via a HOC

This allows entire components to be unmounted when the modal is hidden without affecting the fade in/out of the modal itself.

This also makes it easier to programatically dismiss a modal without having to copy the visibility all over the place, and makes working with props much simpler in those modal components

resources/scripts/context/ModalContext.ts

@@ -0,0 +1,15 @@
+import React from 'react';
+
+export interface ModalContextValues {
+    dismiss: () => void;
+    toggleSpinner: (visible?: boolean) => void;
+}
+
+const ModalContext = React.createContext<ModalContextValues>({
+    dismiss: () => null,
+    toggleSpinner: () => null,
+});
+
+ModalContext.displayName = 'ModalContext';
+
+export default ModalContext;