Split DB Updates into seperate files, with the cutoff being 2.0.0

admin/database_updates/2.3.1.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * ITFlow - Database update to version 2.3.1 (from 2.3.0)
+ * Included by admin/database_updates.php - do not access directly
+ */
+
+defined('FROM_DB_UPDATER') || die("Direct file access is not allowed");
+
+    // Migrate Payment Methods from Categories Table to new payment_methods table
+    $sql_categories = mysqli_query($mysqli, "SELECT * FROM categories WHERE category_type = 'Payment Method' AND category_name != 'Stripe' AND category_archived_at IS NULL");
+
+    while ($row = mysqli_fetch_assoc($sql_categories)) {
+        $category_name = escapeSql($row['category_name']);
+
+        mysqli_query($mysqli,"INSERT INTO payment_methods SET payment_method_name = '$category_name'");
+    }