Add initial version of Manual Invoice functionality with PDF generation and management

application/ManualInvoiceposition/ManualInvoiceposition.php

@@ -0,0 +1,35 @@
+<?php
+
+class ManualInvoiceposition extends mfBaseModel {
+
+    public function getOption($key) {
+        if(!$this->options) {
+            return null;
+        }
+
+        $options = json_decode($this->options, true);
+        if(!$options || !is_array($options)) {
+            return null;
+        }
+
+        if(array_key_exists($key, $options)) {
+            return $options[$key];
+        }
+
+        return null;
+    }
+
+    public function setOption($key, $value) {
+        if(!$this->options) {
+            $this->options = json_encode([]);
+        }
+
+        $options = json_decode($this->options, true);
+        if(!is_array($options)) {
+            $options = [];
+        }
+
+        $options[$key] = $value;
+        $this->options = json_encode($options);
+    }
+}