Ability for extension to Expand/Collapse intput & output of Notebook cells

[DonJayamanne]

Today we collapse and expand cell input & output using the metadata inputCollapsed and outputCollapsed properties.

I've updated our code base to use the VSC code commands to expand/collapse cell output. We inspect the value of the property outputCollapsed and accordingly fire the command notebook.cell.expandCellOutput or notebook.cell.collapseCellOutput
I.e we're not using the metadata to collapse the cell output.

Question:

• Should we continue updating the metadata to change the UI state?
• Should we use the metadata to only inspect the UI state (treat it as a readonly property) & use commands to collapse/expand cell

@jrieken @rebornix /cc

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• "copy/paste cell" should not copy metadata (#103881)

[jrieken]

/duplicate of #125274