update: remove XSS cleaner and remove XSS vulnerabilities

We've been mostly relying on the 3rd party xss cleaner to make sure user submitted content is clean. This PR fixes up any leftover holes in the bbcode parser that allow xss vulnerabilities, and as a result, the 3rd party library isn't needed anymore. It cleans responsibly by first, running `htmlspecialchars()` over the content, followed by sanitizing the untrusted urls and whitelisting their protocol.

app/Http/Livewire/BbcodeInput.php

@@ -18,7 +18,6 @@ namespace App\Http\Livewire;
 
 use App\Helpers\Bbcode;
 use Livewire\Component;
-use voku\helper\AntiXSS;
 
 class BbcodeInput extends Component
 {
@@ -39,13 +38,13 @@ class BbcodeInput extends Component
         $this->name = $name;
         $this->label = $label;
         $this->isRequired = $required;
-        $this->contentBbcode = $content === null ? (old($name) ?? '') : htmlspecialchars_decode($content);
+        $this->contentBbcode = $content ?? old($name) ?? '';
     }
 
     final public function updatedIsPreviewEnabled(): void
     {
         if ($this->isPreviewEnabled) {
-            $this->contentHtml = (new Bbcode())->parse(htmlspecialchars((new AntiXSS())->xss_clean($this->contentBbcode), ENT_NOQUOTES));
+            $this->contentHtml = (new Bbcode())->parse($this->contentBbcode);
         }
     }