Create index with mapping in one step

[sothawo]

Currently, when an index is created by a ElasticsearchRepository, this is done with two calls two the server. The first creates the index with the settings, the second stores the mappings for the index.

The IndexOperationsand ReactiveIndexOperations must offer methods to do this in one step (aliases can be defined there as well, we need to check if we add these in this first step). This is needed for some things like creating and index with index sorting (#1716). When automatically creating indices. these new methods should be used.