Notebooks code cleanup

[roblourens]

• Review internal APIs
  • NotebookEditorWidget
  • NotebookViewModel
  • NotebookTextModel#applyEdits
• More work on notebookExecutionService.ts (Notebook cell execution isn't managed in the renderer #125668)
• Clean up cellRenderer.ts
• CSS cleanup Clean up notebook CSS #140133

[vscode-triage-bot]

Pinging notebook topic followers: @claudiaregio @rchiodo @greazer @DonJayamanne @jilljac @IanMatthewHuff @tanhakabir @dynamicwebpaige

[rebornix]

My wish list of internal API of the notebook editor component:

• No .viewModel usage in contrib
  • This means we would need API on NotebookEditorWidget
• Unify mulit-selection aware notebook actions

[roblourens]

I think probably everything except my cellRenderer task is done? Anything else you plan to do?

[rebornix]

Yeah, the only thing left is polishing cell renderer. Let's finish that next month.