[BUGFIX] Improve l10n_mode config for sys_file_reference

Since the rendering in the Frontend does not merge the values
the mergeIfNotBlank setting is replaced with prefixLangTitle for
the alternative, description and title field.

For the link field the mergeIfNotBlank setting is removed because
a prefix does not make sense there.

Releases: 6.3, 6.2
Resolves: #59972
Change-Id: I242b687a7ce851270022b86561f13eacea4d3949
[BUGFIX] Reset language mode for child object query

This patch makes all child object queries in Extbase ignore the
current language mode which prevents invalid child object references.

Releases: 6.3, 6.2
Resolves: #59971
Change-Id: I0f9e0de9b118fbd3bc49d7b5960285a2a8dce8c8