Better indication of kernel having pending cells

[DonJayamanne]

For #7661

[codecov-commenter]

Codecov Report

Merging #7808 (c8d87c0) into main (1f7fcf5) will decrease coverage by 0%.
The diff coverage is 92%.

❗ Current head c8d87c0 differs from pull request most recent head d5cedec. Consider uploading reports for the commit d5cedec to get more accurate results

@@          Coverage Diff          @@
##            main   #7808   +/-   ##
=====================================
- Coverage     69%     69%   -1%     
=====================================
  Files        363     363           
  Lines      22285   22298   +13     
  Branches    3375    3377    +2     
=====================================
- Hits       15521   15512    -9     
- Misses      5423    5441   +18     
- Partials    1341    1345    +4     

Impacted Files	Coverage Δ
src/client/datascience/jupyter/kernels/types.ts	100% <ø> (ø)
...ent/datascience/jupyter/kernels/kernelExecution.ts	72% <88%> (+3%)	⬆️
...client/datascience/commands/activeEditorContext.ts	91% <100%> (+<1%)	⬆️
src/client/datascience/jupyter/kernels/kernel.ts	73% <100%> (-1%)	⬇️
.../client/datascience/debugLocationTrackerFactory.ts	42% <0%> (-8%)	⬇️
src/client/datascience/jupyter/jupyterDebugger.ts	19% <0%> (-7%)	⬇️
...datascience/editor-integration/codelensprovider.ts	69% <0%> (-5%)	⬇️
...datascience/editor-integration/cellhashprovider.ts	69% <0%> (-3%)	⬇️
...client/datascience/kernel-launcher/kernelDaemon.ts	56% <0%> (-2%)	⬇️
...lient/datascience/variablesView/notebookWatcher.ts	88% <0%> (+1%)	⬆️