Custom Audio: Music transitions

With streamed music, not all track transitions will result in a fade out. For example, when picking up the master sword the temple of time music will just end abruptly and the master sword music will play. This also happens in Ganondorf's castle when he stops playing the organ. Now i know since these aren't sequences you cant have the same kind of fade effect that the game normally does but a basic fade out would be acceptable.

Start by reproducing the streamed-music transitions when picking up the Master Sword and when Ganondorf stops playing the organ. Trace the custom audio transition handling for these non-sequence changes and verify that the outgoing track fades instead of ending abruptly while the incoming music starts normally.

Written by the indexing model from the issue text.