Automatically collapse comments once they are resolved

[joyceerhl]

1. Have an unresolved comment on a pull request that is open in VS Code
2. Click 'Resolve Conversation'
3. Comment remains open, I still have to manually click collapse

I'd expect that resolving a comment also collapses the comment so that it no longer takes up space, which is what happens on github.com

[alexr00]

This is going to need VS Code API to enable collapsing a comment. Just like the tree view, the comment thread collapsible state cannot be modified by the extension once set to prevent conflict between user state and extension state.

[alexr00]

The setting to control this is comments.collapseOnResolve. It is true by default.