Media renaming causes issues

[3e33]

The little renaming icon lets you rename the file. Two issues here:

1. Adding a space in the name will break Markdown, which doesn't allow spaces in the URL ![Image Text](media://Test Image.jpg) will not work and show the unprocessed markdown on the page.
2. Renaming will not add the file extension, if you rename to just TestImage, then the file will also be TestImage, and if you try to use this inside Markdown without an extension, Grav throws an error. Actually any links without an extension will throw.
   ![Image Text](media://anythinghere) <-- this throws:

call_user_func_array(): Argument #1 ($callback) must be a valid callback, first array member is not a valid class name or object

/system/src/Grav/Common/Page/Markdown/Excerpts.php

                if (array_search($method, array_column($actions, 'method')) === false) {
                    $actions[] = [
                        'method' => $method,
                        'params' => $params,
                    ];
                }
            }
        }
 
        // loop through actions for the image and call them
        foreach ($actions as $action) {
            $matches = [];
 
            if (preg_match('/\[(.*)\]/', (string) $action['params'], $matches)) {
                $args = [explode(',', $matches[1])];
            } else {
                $args = explode(',', (string) $action['params']);
            }
 
            $medium = call_user_func_array([$medium, $action['method']], $args);
        }
 
        if (isset($url_parts['fragment'])) {
            $medium->urlHash($url_parts['fragment']);
        }
 
        return $medium;
    }
 
    /**

[rhukster]

Should be fixed in next release