feat: add currency lister

feat: add currency lister

static currency lister

src/Service/CurrencyListerInterface.php

@@ -0,0 +1,12 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+interface CurrencyListerInterface
+{
+    /**
+     * @return string[]
+     */
+    public function getCurrencies(): iterable;
+}

src/Service/StaticCurrencyLister.php

@@ -0,0 +1,20 @@
+<?php
+declare(strict_types=1);
+
+namespace App\Service;
+
+/**
+ * Represents currency lister loaded from configuration
+ */
+readonly final class StaticCurrencyLister implements CurrencyListerInterface {
+    /**
+     * @param String[] $available_currencies
+     */
+    public function __construct(private array $available_currencies) {
+    }
+
+    public function getCurrencies(): iterable
+    {
+        return $this->available_currencies;
+    }
+}