This commit enhances the UI of the application with the following changes:
- Adds sentiment selection via `FilterChip` components with leading icons and friendly names for each `Sentiment` option.
- Introduces a `TextField` for user comments.
- Implements feedback submission, which resets the selected sentiment and clears the comment field upon clicking the button.
- Shows a snackbar to display feedback success after the button is clicked.
- Improves `FilterChip` styling with `ChipDefaults` properties and uses larger font size.
- Uses `Scaffold` to provide a structure for the app.
