ref panel: keep open if user clicks on def inside preview code view

Created by: mrnugget

This fixes the issue reported here: https://github.com/sourcegraph/sourcegraph/discussions/35668#discussioncomment-3047580

It fixes it differently than I described there, but I think it now works as expected:

https://user-images.githubusercontent.com/1185253/181267371-38d18bf9-53e3-4f7d-be88-8d238f7ab2e0.mp4

Test plan

• Manual testing and existing tests, see video above

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.