Configurable rate rounding (#5734)

* added invoice hydration of the issuer object
* added "rate calculator" mode
* new config to select rounding mode
* replace static calls with dependency injection

tests/Export/Base/HtmlRendererTest.php

@@ -48,9 +48,7 @@ class HtmlRendererTest extends AbstractRendererTestCase
         self::assertFalse($sut->isInternal());
     }
 
-    /**
-     * @group legacy
-     */
+    #[Group('legacy')]
     public function testLegacy(): void
     {
         $sut = $this->getAbstractRenderer();