In a case when translation is not set correctly in a template
(e.g. 'helpTooltipSendPreview': helpTooltipSendPreview)
it's value might be evaluated as null and trigger a deprecation warning on PHP8.1.
[MAILPOET-4243]
A translator accidentally used a new line character in the translated
string and that broke JS code we generate in Twig helper function.
We don't want to support new lines in translated strings so as a fix
we just remove those characters to prevent the error in case it happens again.
[MAILPOET-4153]
