Update to use shared memory among instances

[ardura]

Opening this issue as an enhancement in case someone more knowledgeable than me want to try. I looked into the shared memory crates rust provides but encountered a few issues looking into this possibility since the data stored is a vecdeque it can dynamically grow and shrink which makes shared memory complex. Additionally mismatches between instances become possible with this structure so I'm thinking it would be closer to a major update to the code to get this working.

The use case for this came from Bitwig only allowing 1 sidechain unlike other DAWs

[ardura]

Scrollscope has changed to use vec<f32> now for the buffers instead of vecdequeues (

Scrollscope/src/lib.rs

Line 31 in d099cc6

struct ChannelBuffer {

) but that still doesn't make this issue much clearer to me