[Feature] dynamic index_class_mapping ?

hello,

so I need to build a lot of indexes...
the naming of these indexes is dynamic, but I do use a predefined prefix `av_%%indexname%%`
all the indexes do use the same mapping and map to the same class

as the naming is dynamic, I can not list all of them in the configuration...
at runtime, the request tells me on which index I should use.

requests work fine...
BUT when building the resultSet at the end of `\Elastica\Search::search`, using the injected `BuilderInterface` the request fails because the class mapping is unknown

so before looking into injecting a custom `BuilderInterface`, I was wondering if there were ways to either use wildcards for the mapping or inject a mapping at runtime ?

thanks a lot
Dmitri