refactor(ui): Migrate components to ui-next (#4930)

Co-authored-by: Dan Rukas <dan.rukas@gmail.com>

extensions/default/src/ViewerLayout/index.tsx

@@ -1,7 +1,7 @@
-import React, { useEffect, useState, useCallback, useRef } from 'react';
+import React, { useEffect, useState, useCallback } from 'react';
 import PropTypes from 'prop-types';
 
-import { InvestigationalUseDialog } from '@ohif/ui';
+import { InvestigationalUseDialog } from '@ohif/ui-next';
 import { HangingProtocolService, CommandsManager } from '@ohif/core';
 import { useAppConfig } from '@state';
 import ViewerHeader from './ViewerHeader';