AMADEUS: move widgets stuff inside the widgets module

src/rust/amadeus-rs/amadeus/src/amadeus.rs

src/rust/amadeus-rs/amadeus/src/cards/card.rs

src/rust/amadeus-rs/amadeus/src/main.rs

src/rust/amadeus-rs/amadeus/src/widgets/action_menu.rs

src/rust/amadeus-rs/amadeus/src/widgets/mod.rs

src/rust/amadeus-rs/amadeus/src/widgets/playlists.rs

src/rust/amadeus-rs/amadeus/src/widgets/window.rs

src/rust/rs_repo/.cargo/config.toml

src/rust/rs_repo/Cargo.toml

src/rust/rs_repo/src/lib.rs