One bugfix, one new feature and small improvements

[BUGFIX] Removed l10n_mode=exclude for 2 event fields #539

This fixes a problem with registrations saved in other languages than the default language. The problem was introduced in version 3.0.0. It is recommended to update to version 3.0.2

[FEATURE] Use registration data as sender for admin emails #542
[TASK] Removed nimut/typo3-complete as composer dependency
[TASK] Enable filtering in fe_groups fields #534