[DataGrid] Support for multiple IAsyncQueryExecutor registrations

[miguelhasse]

Pull Request

📖 Description

AsyncQueryExecutorSupplier modified so it looks-up multiple IAsyncQueryExecutor registrations and returns the first one that supports the provided IQueryable items source.

[vnbaaij]

Can you give an example of how and why this is handy/better

[miguelhasse]

@vnbaaij this change allows an application to use multiple different IQueryProvider implementations instead of a single one. Suppose for instance you want to use EF Core's DataContext and DataServiceQuery for OData queries.
I'm actually working on a IAsyncQueryExecutor adaptor for DataServiceQuery.

[vnbaaij]

I'm totally not up to speed on EF so don't know what DataServiceQuery does. But judging from the code this change does no do any harm.
Let's give @dvoituron a chance to review as well.

[dvoituron]

I don't have much experience of this either :-)

On the other hand, it would be interesting to add a Unit Test.
At the moment we don't have many tests for the FluentDataGrid, but we're working on the next version v5, which will require all features to be unit-tested. And as you have more experience than we do, adding a test right now would be great. Otherwise we will have to temporarily disable this feature :-(

[miguelhasse]

@dvoituron sure I'll take care of adding unit tests for this feature.