Disable cache in favor of ChluDB

[fazo96]

At the moment, marketplace public keys and validation status are cached in our "cache" module.

The cache module should be removed and the ChluDB should be used instead to cache validation status.

For marketplace public keys, a new solution has to be found. Options are:

• just query the ChluDB for already validated review records from the same marketplace and extract the key locations
• keep using the cache module
• figure out a new way