Improve annotations

[robbycbennett]

Problem(s) this feature will solve

Add the ability to add, edit, and delete annotations manually.

Describe the solution you'd like

• Idea 1: It should be added to the hover information.
• Idea 2: It should be added to the space on the right, implemented like [GitLens](https://marketplace.visualstudio.com/items?
• Idea 3: Add a sidebar that lists annotations.

Ideas for organization and filtering:

• Group by author
• Group by file
• Only the annotations in the current file
• Only the annotations on the current line
• Only the annotations for the current entity

Later:

• Handle the UI problem of entities not declared in the current file (in Understand, there's a popup)
• Highlight card of the current line/entity
• Highlight current line/entity of the selected card (give it a try)

Do the same for AI Overview

• Look for the built-in markdown functionality
• Refresh button (vscode icon "refresh"), no edit or delete

[groke]

Carnegie Mellon University would really like to use annotations heavily, and part of that is using them in the VS Code plugin

Requested by Ryan Karl rmkarl@sei.cmu.edu

[robbycbennett]

For the future build 1222, I added annotations into the hover info.