Delete redundant user rules if superseded by a higher rule

### Issue Details

As an example, let’s say we want to block subdomain-example.google.com, so find it in the query log, and block it.

Then we decide, we don’t actually want google.com to be accessible at all, and decide to block it.

Now we have both of these rules in the user rule editor as blocked, but blocking google.com supersedes subdomain-example.google.com.

### Proposed solution

In this instance it would be good if AdGuard DNS displayed a prompt to the user to request permission to remove redundant rules from the user rules editor.

### Alternative solution

Notify user that there may be redundant rules.