Update the notebooks for the v0.2.0 online lab

[juntyr]

• small code style improvements in the new example dataset notebooks
• updated compression to use the new fcbench.compressor.compress_decompress API
• updated Markdown admonitions to use the newly installed jupyterlab-myst in the online lab

[juntyr]

@SF-N These updates should now be good to go (if I manage to fix the loading messages, I'll do that as a follow-up PR). Mostly the PRs update the admonitions so that jupyterlab-myst, a new extension installed in the online lab, can render them.

I also included some small code style improvements.

[juntyr]

@SF-N I've now also fixed the missing package loading messages and they are now back