TYPO3 Core

Missing topics that should be adressing:
- "Subsubtype" resolving
- childTca features
- colon ":" in type field
- "." notation - should we keep this?
- Add caching per Schema
- Should we re-add systemFields
- Add fields to schema, that have not been added to a schema but are configured in ctrl (hidden, or languageField or l18n_parent)
- Bugfix: Ensure that systemFields are included in subschema fields
- RelationMap Builder should get FFT per DI

Adding tests:
- Tests for Flex Field resolving in RelationMapBuilder
- Tests in SchemaCapabilities
- Tests: What to do when a field is in ctrl, but not in column? (see original patch with styleguide changes)
- Tests getSubSchemaDivisorField -> check what happens if your TCA type does not contain this field