[BUGFIX] Catch error in GeneralUtility::validEmail and GeneralUtility:isValidUrl

If a wrong email address or URL is parsed and the domain cannot be converted,
an exception is thrown by \Mso\IdnaConvert\IdnaConvert::encode(). This
exception needs to be caught.

Resolves: #81471
Releases: master, 8.7, 7.6
Change-Id: I76f9b8898655d9220e5176a60f388067a6c493b3
Reviewed-on: https://review.typo3.org/53121


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>