Add delete button on the query page

[grigorescu]

I'd like to clear the history for an IP once I query it.

[JustinAzoff]

This can be done, but it's a little tricky. BHR needs to ensure that the entries are unblocked before deleting, otherwise the blocks will get orphaned. For an old record that is already unblocked, this is easy, but for a current block it would have to be an async operation so it can wait for the downstream blockers to catch up.