Repo popover "Show more" button or clicking in text field dismisses the popover

Created by: sqs

Repro:

1. Go to any Sourcegraph page with the repo file header, such as https://sourcegraph.com/github.com/sourcegraph/docsite/-/blob/cmd/docsite/site.go#L87
2. Press the down caret next to the repo name to open the repo popover
3. Press "Show more" or click in the text field

Expected: normal behavior from clicking one of those things Actual: the popover is dismissed (closed)

Note: This problem does not occur in the rev popover (try the commits tab, which usually has enough results it needs to show a "Show more" button)