added user-has-manager-permissions dav prop; added principal model and simplified the ACL code with it

lib/Model/Principal.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace OCA\OrganizationFolders\Model;
+
+use OCA\OrganizationFolders\Enum\PrincipalType;
+
+class Principal implements \JsonSerializable {
+    public function __construct(
+		private PrincipalType $type,
+        private string $id,
+	) {
+        // check if id fits format
+    }
+
+    public function getType(): PrincipalType {
+		return $this->type;
+	}
+
+    public function getId(): string {
+		return $this->id;
+	}
+
+	public function jsonSerialize(): array {
+		return [
+			'type' => $this->type->value,
+			'id' => $this->id,
+		];
+	}
+}