For #271167
This makes it so our built-in extensions can mostly be built using `tsc` on the command line. Previously the extensions were picking up a lot of typing info from the root `node_modules` that meant they weren't truly independent
* Finalize NotebookEditor api proposal
Fixes#149271
This finalizes most parts of the NotebookEditor api proposal. I haven't removed the proposal entirely as there are still a few parts being left behind:
- The deprecated properties/functions
- A few contribution points such as `notebook/cell/executePrimary`
* remove extra quote