feat: add monthly budget field and statistics (#329)

migrations/000018.php

@@ -0,0 +1,15 @@
+<?php
+
+/*
+This migration adds a column to the users table to store a monthly budget that will be used to calculate statistics
+*/
+
+/** @noinspection PhpUndefinedVariableInspection */
+$columnQuery = $db->query("SELECT * FROM pragma_table_info('users') where name='budget'");
+$columnRequired = $columnQuery->fetchArray(SQLITE3_ASSOC) === false;
+
+if ($columnRequired) {
+    $db->exec('ALTER TABLE user ADD COLUMN budget INTEGER DEFAULT 0');
+}
+
+?>