Fix memory footprint after using WebUI for a long time

WebUI consumes more and more memory after you use it.

To observe/reproduce the issue, you can repeat ~ 100 times a navigation from Root to Default Domain then Sections then one section. You'll see that the memory footprint for the WebUI tab increases between 10MB to 25MB per iteration, until it will reach 1GB as you can see on the attached screenshot

As soon as one navigates to another site (like google news), you'll see the tab memory footprint will get back to 150-200MB. So the memory is really kept by something related to WebUI

Expected behavior: the memory footprint for this scenario should stay under 200MB

Tested with Chrome 124.0.6367.9