Don't store JSON in level DB

[renepickhardt]

as discussed with @sebschlicht it might make sense to store objects in as byte array in level db.

First profile in the middleware if parsing json with all the reflections is really a bottleneck

if so: move this code from https://github.com/Metalcon/middleware/blob/f15162d943a625dfcf535f70359fd6b0b0d572e2/src/main/java/de/metalcon/middleware/core/SddOutputGenerator.java to static data delivery write requests and change the response Classes and API of static data delivery.