Feature: #96961 - Backend routes contain composer package name

See Issue #96961

Description

Request objects in the backend already contain the resolved route object as attribute. These route objects now contain the composer package name of the package (“extension”) that defined the route as option:

/** @var \TYPO3\CMS\Backend\Routing\Route $route */
$route = $request->getAttribute('route');
// Example return: "typo3/cms-backend" when EXT:backend defined that route.
$packageName = $route->getOption('packageName');

Impact

The package name can be useful for filesystem lookups or to bind configuration based on package name to it.