Code Insights: Add drill-down story and regexp filter panel component

Created by: vovakulikov

Closes https://github.com/sourcegraph/sourcegraph/issues/23189

Context

This PR adds a new visual component for the insight card component - the drill-down filters panel. You can find the designs here

This PR adds this UI only to the storybook insight card story since we haven't implemented a drill-down logic yet. The logic will be added in the separate PR (here is the ticket for it)

Known limitation and tech details

• [Tech] Popover was implemented by UncontrolledPopover from the reactstrap package. Since reach UI popover doesn't have some needed logic like close on escape or close on outside click. Eventually, I think we should have such a component in our wildcard package but for now, this PR uses popover from reactstrap.
• [Designs] Filters button has only one state (compact mode). The logic for that visual behavior will be added in separate PR.