Make transactional actions properly transactional

[nikitaDanilenko]

Currently, the resolution actions in the graphQL queries are not transactional in the database sense, because the individual components are fetched without a transaction scope. It is prudent to adjust the handling to a proper transaction logic.

One possible solution is to provide companion instances to the GraphQLServices class, and to use those in the resolution queries, followed by a db.runTransactionally