Improve fluidity of interactions

Optimize several parts of MuSink interactive to keep lags and latencies small.

• Use only background / compute threads for the kernel operations.
• Make all calls to query_workspace asynchronous
• Communicate epsilon and rho via channels, not via query_workspace
• Prevent axis creation (largely done for rows already)
• The biggest issue: check how precompilation / PackageCompiler can improve first-time-to-plot behavior