Add ExportAsKeyed extension

[mcdis]

We are already have ExportAs extension.
Add ExportAsKeyed extension:
static IFluentExportStrategyResgistration<TImpl> ExportAsKeyed<TImpl,T>(this IExportRegistrationBlock _this, object key);
shorten equalent of
Export<TImpl>().AsKeyed<T>(key);

[ipjohnson]

Hi @mcdis

I think I can add that, I’ll try and find some time in the coming week to add it and do a beta.

[ipjohnson]

@mcdis, I pushed out a beta with this change

[ipjohnson]

closing as released in 6.4.2