feat: add possibility to register additional tables to skip for relations

[jackd248]

E.g.
$GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['xima_typo3_manual']['relations']['additionalTablesToSkip'] = ['tx_kesearch_filters'];

[maikschneider]

Thanks!

I guess it could be simplified:

$tablesToSkip = array_merge($tablesToSkip, $GLOBALS['TYPO3_CONF_VARS']['EXTCONF']['xima_typo3_manual']['relations']['additionalTablesToSkip'] ?? []);

Should we add a ext_conf_template.txt?

[jackd248]

Should we add a ext_conf_template.txt?

I would rather see this as a customization in ext_localconf.php.