Refactor components, fix alignments

frontend/src/App.tsx

frontend/src/backendconnection/communication.ts

frontend/src/connectionstatus/ConnectionStatusBar.tsx

frontend/src/player/InstantReplayButton.tsx

frontend/src/player/Player.tsx

frontend/src/player/PlayerButtonBar.tsx

frontend/src/player/PlayerControlButton.tsx

frontend/src/store/store.ts

frontend/src/url/InputBar.tsx

frontend/src/url/UploadButton.tsx

frontend/src/url/UrlSlice.ts

frontend/src/url/UrlTextfield.tsx

frontend/src/url/style.css