feat(tax): implement tax rate history tracking and API endpoints

src/Config/Repository/SiteConfigRepository.php

@@ -10,8 +10,6 @@ class SiteConfigRepository extends ServiceEntityRepository
 {
     // Default values returned when a key is missing from DB
     private const DEFAULTS = [
-        'commission_enabled'         => '0',
-        'commission_percent'         => '0',
         // financial engine
         'appointment_commission_enabled' => '0',
         'upgrade_commission_enabled'     => '0',

src/Config/Repository/TaxRateHistoryRepository.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Config\Repository;
+
+use App\Config\Entity\TaxRateHistory;
+use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
+use Doctrine\Persistence\ManagerRegistry;
+
+class TaxRateHistoryRepository extends ServiceEntityRepository
+{
+    public function __construct(ManagerRegistry $registry)
+    {
+        parent::__construct($registry, TaxRateHistory::class);
+    }
+
+    public function save(TaxRateHistory $entity, bool $flush = true): void
+    {
+        $this->getEntityManager()->persist($entity);
+        if ($flush) $this->getEntityManager()->flush();
+    }
+}