WIP: Offline mode in jupyterlab

[mwouts]

Will close #70

[codecov-commenter]

Codecov Report

Merging #74 (4d8eb7c) into main (2862a8b) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #74   +/-   ##
=======================================
  Coverage   96.66%   96.66%           
=======================================
  Files          14       14           
  Lines         330      330           
=======================================
  Hits          319      319           
  Misses         11       11           

Impacted Files	Coverage Δ
itables/version.py	100.00% <100.00%> (ø)

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[mwouts]

I am not going to take this one, instead I'll merge #76