Support collapsing/expanding notebook cell comments

[rehmsen]

Does this issue occur when all extensions are disabled?: Yes/No

• VS Code Version: macOS 15.1.1 (24B91)
• OS Version: 1.96.1

Steps to Reproduce:

1. Create a review comment on a notebook cell.
2. Press the collapse button.

Expected:
Collapses the comment somehow.

Actual:
Nothing happens.

---

Looks like this was never implemented for notebooks:

vscode/src/vs/workbench/contrib/notebook/browser/view/cellParts/cellComments.ts

Line 74 in 8467007

collapse: () => { }

I guess one challenge in implementing is coming up with a UX for collapsed comments and how to uncollapse them, given there is no line gutter icon which is used on text files for that. Maybe we could have a similar red icon in the bottom margin that also has the language picker on the far right. There is some space there, and it is relatively close to where the comments would be...

What do you think, @rebornix?

[vs-code-engineering]

Thanks for creating this issue! It looks like you may be using an old version of VS Code, the latest stable release is 1.96.1. Please try upgrading to the latest version and checking whether this issue remains.

Happy Coding!