refactor: Migrate webviews from React 16 + react-bootstrap to React 19 + @vscode-elements/elements#1616

chagong merged 5 commits into

mainmicrosoft/vscode-java-pack:mainfrom

feat/migrate-react19-vscode-elementsmicrosoft/vscode-java-pack:feat/migrate-react19-vscode-elementsCopy head branch name to clipboard