Add probe support to `@user@domain.tld` search string format

mod/follow.php

@@ -60,8 +60,7 @@ function follow_content(App $a)
 
 	$uid = local_user();
 
-	// Issue 4815: Silently removing a prefixing @
-	$url = ltrim(Strings::escapeTags(trim($_REQUEST['url'] ?? '')), '@!');
+	$url = Probe::cleanURI(trim($_REQUEST['url'] ?? ''));
 
 	// Issue 6874: Allow remote following from Peertube
 	if (strpos($url, 'acct:') === 0) {

src/Console/Contact.php

@@ -25,6 +25,7 @@ use Console_Table;
 use Friendica\App;
 use Friendica\Model\Contact as ContactModel;
 use Friendica\Model\User as UserModel;
+use Friendica\Network\Probe;
 use Friendica\Util\Temporal;
 use RuntimeException;
 use Seld\CliPrompt\CliPrompt;
@@ -153,6 +154,8 @@ HELP;
 			}
 		}
 
+		$url = Probe::cleanURI($url);
+
 		$contact = ContactModel::getByURLForUser($url, $user['uid']);
 		if (!empty($contact)) {
 			throw new RuntimeException('Contact already exists');

src/Module/Debug/Probe.php

@@ -44,6 +44,7 @@ class Probe extends BaseModule
 		$res  = '';
 
 		if (!empty($addr)) {
+			$addr = NetworkProbe::cleanURI($addr);
 			$res = NetworkProbe::uri($addr, '', 0);
 			$res = print_r($res, true);
 		}