Advanced Settings -> Content Blockers screen does not show "Loading into Safari" state

[ameshkov]

The point of this screen is to show the current content blockers' statuses. "Loading into Safari" is one of the important (if not the most important) states so the fact that it's missing from that screen seems is very wrong.

This screen should show every state the content blocker goes through:

1. Rules conversion
2. Loading into Safari
3. Status (if there was an error loading the filter in Safari, it should be indicated there).