DayOfWeek is an enum as defined at https://schema.org/DayOfWeek
We missed the PublicHolidays enum value when building
`getDaysOfWeekWithMondayFirstWeekDay()` which is used in templates to
get ordered result.
Opening hours for public holidays were not rendered, which is now fixed.
- Removed individual converters for TYPO3.
Conversion is now handled in a single converter.
- The new converter will import necessary dependencies upfront, e.g.
town or organisation.
- Move import state into extra class.
Relates: #34
This should ensure rendering works as expected.
Most important: This ensures data is available in frontend templates.
Add dev dependency to fluid_styled_content. This is necessary to test
our rendering integration with fluid_styled_content defaults.
Relates: #34
