Audio source lost on rename

[Devvypaws]

Description

Waveform sources do not keep track of audio sources by id, but rather name. So if you rename an audio source, the Waveform no longer pulls from the audio source. You must manually set all Waveform sources to use the new name, or you must rename it to the old name.

Steps to Reproduce

1. Create a Waveform and an audio source
2. Open the Waveform source's properties
3. Set the Audio Source to the audio source
4. Press OK
5. Rename the audio source

Expected Result

The Waveform source continues working, and its Audio Source is the same audio source as before, but with the new name.

Actual Result

The Waveform source stops pulling from the audio source, and its Audio Source is None and must be set again.

[phandasm]

I really don't want to break existing configs, but I'll see about switching to id for new sources with name as fallback.