ISPN-3472 Add all modules required by remote-query
Reformat and removed unused imports
ISPN-3346 Find MimeMetadata externalizers import REST server services
ISPN-3290 CacheStore SPI redesign alignment

- Custom and legacy stores currently don't work and code / tests have been adapted for this.
ISPN-3482 Do not use LevelDB implementation classes in the server code

- Make the possible LevelDB implementation modules optional