feat: 🎸 New modal provider (#1110)

* feat: 🎸 New modal provider

A new modal provider/context component to unify modal related code and
simplify modal use

Closes: #1086

* refactor(ModalContext): Keep current modal lib

* Update modal provider version according to PR #1116

* Update modal provider props to use inner props

* Add custom class prop

* CR Update: Refactor provider to extract specific modal

* Fix modal import

* CR Update: Move from spread to object assign

* CR Update: Add proptypes, use classnames dependency over interpolation and rename modal

platform/ui/src/components/index.js

@@ -16,6 +16,7 @@ import { QuickSwitch } from './quickSwitch';
 import { RoundedButtonGroup } from './roundedButtonGroup';
 import { SelectTree } from './selectTree';
 import { SimpleDialog } from './simpleDialog';
+import { OHIFModal } from './ohifModal';
 import {
   PageToolbar,
   StudyList,
@@ -52,4 +53,5 @@ export {
   AboutModal,
   UserPreferences,
   UserPreferencesModal,
+  OHIFModal,
 };