From previous PRs, we've already added support for include_type_name to
the get mapping API. We had also taken an approach to the HLRC where the
server-side `GetMappingResponse#fromXContent` could only handle typeless
input.
This PR updates the HLRC for 'get mapping' to be in line with our new approach:
* Add a typeless 'get mappings' method to the Java HLRC, that accepts new
client-side request and response objects. This new response only handles
typeless mapping definitions.
* Switch the old version of `GetMappingResponse` back to expecting typed
mappings, and deprecate the corresponding method on the HLRC.
Finally, the PR also does some small, related clean-up around 'get field mappings'.
This change adds deprecation warning to the indices.get_mapping API in case the
"inlcude_type_name" parameter is set to "true" and changes the parsing code in
GetMappingsResponse to parse the type-less response instead of the one
containing types. As a consequence the HLRC client doesn't need to force
"include_type_name=true" any more and the GetMappingsResponseTests can be
adapted to the new format as well. Also removing some "include_type_name"
parameters in yaml test and docs where not necessary.
* Replace custom type names with _doc in REST examples.
* Avoid using two mapping types in the percolator docs.
* Rename doc -> _doc in the main repository README.
* Also replace some custom type names in the HLRC docs.