insights: aggregations reset the ui mode to sidebar when drilling into chart

Created by: chwarwick

Updates the bar click logic to reset the current UI mode to Sidebar if it isn't already. I avoided the pings because this is not a user taken.

resolves https://github.com/sourcegraph/sourcegraph/issues/41447

Test plan

Expand the aggregation, then click a bar and see the aggregations return to the sidebar with updated search results.

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.