2sxc 9.7 with JSON Persistence and File-Based Types

A lot of internal features necessary for future enhancements:

1. Full JSON serialization and deserialization of content-types
2. Dynamic Entities with known Type-Definition
   1. Definition of Dynamic Entities - which are entities with unknown content-type
   2. Full JSON serialization and deserialization of such dynamic entities
3. File system provider DataLoader which uses the file-System as a repository
   1. Currently only providing Global content-types
4. New Global Content-Type Providers
   1. Code provided content-type definitions
   2. file-system provided global content-type definitions (using File System Provider)
   3. System loader automatically picks up "globally" registered content-types from file system
5. Db changes
   1. Added fields AppId and ContentType to Entities table
   2. System can now load json entities from db
   3. DB can now store entities which are not registered in the db
6. DataSources used in the visual query designer can now request custom named content-types