Implement EZP-20231: Cluster support in FieldTypes

This PR implements cluster support for binary FieldTypes (Image, BinaryFile, Media) by means of a LegacyFileService.

Tasks:
- [x] Refactor the FileService
- [x] Create LegacyFileService
- [x] Adapt FieldType: BinaryBase
- [x] Adapt FieldType: Image
- [x] Adapt FieldType: BinaryFile
- [x] Adapt FieldType: Media
- [x] Refactor MetaData handling
- [x] Implement ImageSize metadata handler