fix issues with contour animation when contour compression is disabled

[veggiesaurus]

As discovered by @kswang1029, playing back an animation with contours at a high frame rate can result in garbled ICD messages when using the MacOS electron app. @ajm-asiaa worked out that this only occurs with the electron app (and not the homebrew install) because contour compression is disabled.

This may be because we're instructing uWebSockets to compress the uncompressed contour messages using deflate. Perhaps the buffer size is too small 🤔

[veggiesaurus]

now that I know what I'm looking for, I can reproduce this error on Ubuntu 20.04 in the dev branch as well. It seems to happen more frequently when the dev console is open (because network data is inspected, leading to reduced throughput of data)

2021-06-18.16-17-41.mp4