Install IPyKernel into venv without using Python ext

[DonJayamanne]

For #1253
For #421

[DonJayamanne]

If you notice, I've fixed a typo (installed spell checker, for some reason this was uninstalled on my mac)

[codecov-commenter]

Codecov Report

Merging #8456 (5dbc907) into main (8f6665e) will decrease coverage by 0%.
The diff coverage is 11%.

@@          Coverage Diff          @@
##            main   #8456   +/-   ##
=====================================
- Coverage     71%     71%   -1%     
=====================================
  Files        376     376           
  Lines      23814   23816    +2     
  Branches    3669    3669           
=====================================
- Hits       17124   17116    -8     
- Misses      5200    5210   +10     
  Partials    1490    1490           

Impacted Files	Coverage Δ
src/client/common/installer/backupPipInstaller.ts	23% <6%> (-2%)	⬇️
src/client/common/installer/productInstaller.ts	52% <50%> (+1%)	⬆️
...ent/datascience/jupyter/pythonVariableRequester.ts	68% <0%> (-6%)	⬇️
src/client/datascience/jupyter/kernels/kernel.ts	77% <0%> (-1%)	⬇️
src/client/debugger/jupyter/kernelDebugAdapter.ts	77% <0%> (-1%)	⬇️
src/client/datascience/baseJupyterSession.ts	76% <0%> (+<1%)	⬆️
...ence/editor-integration/cellHashProviderFactory.ts	100% <0%> (+2%)	⬆️