refactor: replace custom CRM with Monica fork

app/Services/DavClient/Utils/Traits/HasCapability.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Services\DavClient\Utils\Traits;
+
+use Illuminate\Support\Arr;
+
+trait HasCapability
+{
+    /**
+     * Check if the subscription has the give capability.
+     *
+     * @param  string  $capability
+     * @return bool
+     */
+    private function hasCapability(string $capability): bool
+    {
+        return Arr::get($this->sync->subscription->capabilities, $capability, false);
+    }
+}

app/Services/DavClient/Utils/Traits/WithSyncDto.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Services\DavClient\Utils\Traits;
+
+use App\Services\DavClient\Utils\Model\SyncDto;
+use App\Http\Controllers\DAV\Backend\CardDAV\CardDAVBackend;
+
+trait WithSyncDto
+{
+    /**
+     * @var SyncDto
+     */
+    protected $sync;
+
+    /**
+     * Get carddav backend.
+     *
+     * @return CardDAVBackend
+     */
+    protected function backend(): CardDAVBackend
+    {
+        return $this->sync->backend();
+    }
+}