Problem

We plan to introduce new engines that may provide us term tagging functionality.

Code base in current state doesn't have abstraction layer that may allow us to easily use some system setting to choose what engine will be used.

Solution

Obviously we need to provide some abstraction to cover desired functionlity.

Engines in plans do not provide same quality for every language and as so we wanna setting to be able to set for each language separately.

For start we will introduce this config as system level to not introduce UI for it too soon.

Plan for now is to have it as map with language => engine.

Also we need to provide default engine as fallback: for now that will be Term Tagger without any additional setting in DB. But we may change this later on.