Code Insights: Fix "default applied filter" text appearance

Created by: vovakulikov

@AlicjaSuska originally found this issue during testing the Search Context filter's PR here https://github.com/sourcegraph/sourcegraph/pull/34620

I've noticed one thing about 'default filters applied' message that needs correcting (probably in a separate issue):

1. open insights with default filters applied - 'Default filters applied' text is displayed, pink dot displayed
2. Change filters (reduce scope) / reset filters - text should disappear (now, it's still being displayed), dot disappears

Here is the loom showing what's happening and the Figma design (diagram) that shows the desired flow.