foris: install foris only if it is required for pakon

This removes explicit request for foris and installs it only if pakon is requested. Any other request for foris package is now only installed if foris is going to be.

The stylistic tweak here is removal of condition checks for for_l10n function. This function is defined in utils.m4 and thus directly in all files so this condition made no sense.

I noticed that we still unconditionally install Foris. This should no longer be. We decided that phasing out of Foris is going to be in such a way that first we remove it from default installation for some time and only then we drop it. We plan to drop it with %Turris OS 6.0 so this is long overdue.