Delete api: remove broadcast delete if routing is missing when required

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 #9123
Closes #10136

docs/reference/migration/migrate_2_0.asciidoc

@@ -161,6 +161,12 @@ shards aren't being kept track of. From version 2.0 the stats in the `_shards` h
 of an index. The http status code is left unchanged and is only based on failures that occurred while executing on
 primary shards.
 
+=== Delete api with missing routing when required
+
+Delete api requires a routing value when deleting a document belonging to a type that has routing set to required in its
+mapping, whereas previous elasticsearch versions would trigger a broadcast delete on all shards belonging to the index.
+A `RoutingMissingException` is now thrown instead.
+
 === Mappings
 
 * The setting `index.mapping.allow_type_wrapper` has been removed.  Documents should always be sent without the type as the root element.

src/main/java/org/elasticsearch/action/ActionModule.java

@@ -129,8 +129,6 @@
 import org.elasticsearch.action.count.TransportCountAction;
 import org.elasticsearch.action.delete.DeleteAction;
 import org.elasticsearch.action.delete.TransportDeleteAction;
-import org.elasticsearch.action.delete.TransportIndexDeleteAction;
-import org.elasticsearch.action.delete.TransportShardDeleteAction;
 import org.elasticsearch.action.deletebyquery.DeleteByQueryAction;
 import org.elasticsearch.action.deletebyquery.TransportDeleteByQueryAction;
 import org.elasticsearch.action.deletebyquery.TransportIndexDeleteByQueryAction;
@@ -282,8 +280,7 @@ protected void configure() {
                 TransportDfsOnlyAction.class);
         registerAction(MultiTermVectorsAction.INSTANCE, TransportMultiTermVectorsAction.class,
                 TransportShardMultiTermsVectorAction.class);
-        registerAction(DeleteAction.INSTANCE, TransportDeleteAction.class,
-                TransportIndexDeleteAction.class, TransportShardDeleteAction.class);
+        registerAction(DeleteAction.INSTANCE, TransportDeleteAction.class);
         registerAction(CountAction.INSTANCE, TransportCountAction.class);
         registerAction(ExistsAction.INSTANCE, TransportExistsAction.class);
         registerAction(SuggestAction.INSTANCE, TransportSuggestAction.class);