Avoid duplicate types deprecation messages in search-related APIs.

[jtibshirani]

This PR moves the check for using the _type field in queries out of TypeFieldType and into QueryShardContext#fieldMapper.

Currently, we issue two separate deprecation messages when APIs like 'search', 'explain', and 'update by query' include types in the URL, because these APIs create a term filter on _type as part of their execution. Moving the deprecation check into QueryShardContext#fieldMapper lets us avoid these duplicate messages.

[elasticmachine]

Pinging @elastic/es-search

[mayya-sharipova]

@jtibshirani Thanks Julie for following up on this PR.

Is the goal to have only a single deprecation message when a user submits a query that references a type field inside the body? Do we want to have a single deprecation even if a type is also used in the url?

Currently with your PR if we have a type both in the url, and inside the body, we still get 2 deprecation warnings:

[jtibshirani]

Thanks @mayya-sharipova for taking a look. In your example, my goal was indeed to have two deprecation messages, because the user has specified a type in two distinct places. The situation I am trying to avoid is having two deprecation messages when there is only a type in the URL.

[mayya-sharipova]

Thanks Julie! Makes sense!

[jtibshirani]

@elasticmachine run gradle build tests 1