feat: Integrate Melt popover functionality across components

Commit notes

This commit introduces the Melt popover functionality in various components, enhancing user interaction. The AnimatedDropdown, GainMeter, Header, KeyboardShortcuts, and SequencerTrack components have been updated to utilize the new popover system for improved dropdown and menu management. Additionally, the Svelte version has been upgraded to 5.33.0, and the Melt package has been added to the project dependencies for better UI handling.