This commit changes the behaviour of the delete api when processing a delete request that refers to a type that has routing set to required in the mapping, and the routing is missing in the request. Up until now the delete api sent a broadcast delete request to all of the shards that belong to the index, making sure that the document could be found although the routing value wasn't specified. This was probably not the best choice: if the routing is set to required, an error should be thrown instead.
A `RoutingMissingException` gets now thrown instead, like it happens in the same situation with every other api (index, update, get etc.). Last but not least, this change allows to get rid of a couple of `TransportAction`s, `Request`s and `Response`s and simplify the codebase.
Closes#9123Closes#10136