[ENE-49] Fix infinite loop in derivation

[programaker]

When writing a code like: implicit val x: TypedMongoFormat[Something] = io.sphere.mongo.generic.deriveMongoFormat

or given TypedMongoFormat[Something] = io.sphere.mongo.generic.deriveMongoFormat

A compile error happens due to an infinite loop in the derivation process.

This PR aims to fix that, and also add some new features:

• TypedMongoFormat now has an inline apply method cats-style to summon an instance at 0 cost.
• Verification that the derives directive also works (at least for Product types).
• Specs for different ways to derive and summon instances (given, implicit, automatic).

[programaker]

CI won't work anyway, so I'm closing the PR