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
Allows to import entity of type TouristAttraction.
Right now only in German, as this is most important.
Add output of tourist attraction via custom content element.
Still very simple, but can be improved in future updates.
E.g. add info regarding error, or deep link to single import log with
errors, etc.
To provide that, we need to add some more code, which is not necessary
yet.
Provide first basic import mechanism.
It already allows to import entities into TYPO3 database.
Three entities are supported.
Entities are configured through import configuration.
This can be created, viewed, and edited through backend module.
Imports are tracked and accessible from backend module.
Still this is basic.
Importing lists of entities is not supported.
Multiple languages is not supported, etc.
Relates: #8214
