One Way Conversions from CreateIndexRequestDescriptor<TDocument> to CreateIndexRequestDescriptor

[InsperDylan390]

Is your feature request related to a problem? Please describe.
I'm working with elastic in a context using a large number of generic classes. In contexts where it would make sense to perform an action for a set of indexes I run into issues where I would like to setup a request for a given TDocument, but use it in a context that doesn't know about TDocument. For example, creating an instance of CreateIndexRequestDescriptor<TDocument, but then using the untyped Indicies.Create.

Describe the solution you'd like
Perhaps the ability to convert CreateIndexRequestDescriptor and other similar requests from the generic types into their non-generic equivalents?

Describe alternatives you've considered
Alternatively, having a concrete type relationship between the generic and non-generic types would also allow for easy conversion between the two?

Additional context
Add any other context or screenshots about the feature request here.

[sbodese]

hi, it seems for me like some identically issues like here:

#7929