[toggle-core] Update FeatureRepository::remove contract with a Feature instead of FeatureId

[xserrat]

In this epic we need to update the FeatureRepository::remove method contract in order to accept a Feature entity instead of its FeatureId.

Doing so, we'll be able to release the events recorded in the entity to dispatch later on.

This epic will be closed when these issues are closed:

• Update FeatureRepository::remove contract to accept Feature instead of FeatureId toggle-core#30
• Update InMemoryFeatureRepository::remove contract with a Feature instead of FeatureId inmemory-toggle#4
• Update DbalFeatureRepository::remove contract with a Feature instead of FeatureId dbal-toggle#4