Refactor: notebook export

[rebornix]

Re #10152

Export to HTML/PDF/Python is a feature on notebook document, and can be reused by interactive window. Thus we move it out of platform and embed in src/notebooks.

This PR is purely file movement.

• Pull request represents a single change (i.e. not fixing disparate/unrelated things in a single PR).
• Title summarizes what is changing.
• Has a news entry file (remember to thank yourself!).
• Appropriate comments and documentation strings in the code.
• Has sufficient logging.
• Has telemetry for feature-requests.
• Unit tests & system/integration tests are added/updated.
• Test plan is updated as appropriate.
• package-lock.json has been regenerated by running npm install (if dependencies have changed).

[codecov-commenter]

Codecov Report

Merging #10487 (b9d1376) into main (4ed91b2) will decrease coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##            main   #10487   +/-   ##
======================================
- Coverage     71%      71%   -1%     
======================================
  Files        486      486           
  Lines      29161    29161           
  Branches    4902     4902           
======================================
- Hits       20760    20757    -3     
- Misses      6441     6450    +9     
+ Partials    1960     1954    -6     

Impacted Files	Coverage Δ
src/notebooks/export/exportToHTML.ts	100% <ø> (ø)
src/notebooks/export/exportToPDF.ts	66% <ø> (ø)
src/notebooks/export/exportToPython.ts	100% <ø> (ø)
src/notebooks/export/types.ts	100% <ø> (ø)
src/platform/serviceRegistry.node.ts	100% <ø> (ø)
src/telemetry/types.ts	100% <ø> (ø)
src/interactive-window/interactiveWindow.ts	73% <100%> (ø)
...ractive-window/interactiveWindowCommandListener.ts	37% <100%> (ø)
...rc/interactive-window/interactiveWindowProvider.ts	78% <100%> (ø)
src/notebooks/export/exportBase.node.ts	73% <100%> (ø)
... and 18 more