Revert "Remove hover effekt"

packages/app-shell/src/app-shell.js

packages/app-shell/src/auth-menu-button.js

packages/app-shell/src/dbp-app-shell-welcome.js

packages/auth/src/login-button.js

packages/common/dbp-common-demo.js

packages/common/styles.js

packages/file-handling/src/clipboard.js

packages/file-handling/src/styles.js

packages/language-select/src/language-select.js

packages/notification/src/notification.js

packages/qr-code-scanner/src/qr-code-scanner.js

toolkit-showcase/src/styles.js