Feature: #85236 - Infix option to default log file names for FileWriter

See forge#85236


A new option logFileInfix for the FileWriter has been introduced. This allows to set a different name for the log file that is created by the FileWriter without having to define a full path to the file.

The example configuration will use the log file named typo3_special_<hash>.log for any log message stemming from a class from the Vendor\ExtName namespace.

$GLOBALS['TYPO3_CONF_VARS']['LOG']['Vendor']['ExtName']['writerConfiguration'] = [
  \TYPO3\CMS\Core\Log\LogLevel::INFO => [
    \TYPO3\CMS\Core\Log\Writer\FileWriter::class => [
      'logFileInfix' => 'special'


The behaviour for existing FileWriter configurations is not changed.