Update giada to 0.20.0 “Alicanto”.

The Alicanto is a mythological bird of Chilean mythology. According to legend, a miner that follows an alicanto without being noticed by the bird can find rich mineral outcrops or hidden treasures.

Changelog:

• Show progress bar for long operations
• Improved rendering algorithm for sample channels
• Fix wrong sample tail rendering when pitch != 1.0
• Always display play head in Action Editor
• Fix re-initialization order of engine sub-components
• Change 'kill chan' wording to 'stop note' in Action Editor
• Update solo count when deleting a channel
• Update Main Window title when saving a new project
• [Config] Don't skip MIDI device fetching if one of the ports fail to open
• [CMake] Include FLTK as suggested in the official docs
• Add more unit tests for some Channel components
• Minor cleanups and refactoring