🐛 (webview/frontend/CaseView.tsx): Add UI options by adding a "Set As E…

[DawnMagnet]

…xpected Output" button and related styles in app.css

Adds a new button to the CaseView component that allows users to set the output text as the expected output. This button is represented by the "Set" label and is styled with a gray filter, positioning, padding, cursor, and hover effects defined in the app.css file. The purpose of this change is to improve user experience by providing an easy way for users to mark output text as the expected output.