feat: add dedicated test cases to ensure copy and move methods to always overwrite target

Author: tinect

LocalFilesystemAdapter.php

@@ -271,7 +271,7 @@ public function copy(string $source, string $destination, Config $config): void
             $this->resolveDirectoryVisibility($config->get(Config::OPTION_DIRECTORY_VISIBILITY))
         );
 
-        if ( ! @copy($sourcePath, $destinationPath)) {
+        if ($sourcePath !== $destinationPath && ! @copy($sourcePath, $destinationPath)) {
             throw UnableToCopyFile::because(error_get_last()['message'] ?? 'unknown', $source, $destination);
         }