The schema is very flexible and some values are not validated upfront.
This will result in many objects which we currently can not map.
This resulted in an exception breaking the rest of the import.
We now handle the broken mapping and skip those objects with proper
logging.
This allows to continue with import and report and debug those objects
in order to improve the mapping step by step.
Relates: #10198
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
