Action and Operation do not expose $select and $expand over entity types

Action and Operation do not expose $select and $expand over entity types while this is possible for /entity/propertyOfComplexType

Assemblies affected

Microsoft.OpenApi.OData 1.7.5

Steps to reproduce

Register additional function for entity set:

        var fax = builder.EntityType<XFax>();
        fax.Collection.Function(nameof("GetByNumber"))
            .ReturnsFromEntitySet<XFax>("Fax")
            .NonNullable()
            .Parameter<string>("number").NonNullable();

Expected result

GetByNumber should have both $select and $expand operations because XFax is Entity type

Actual result

No operations available

Additional detail

I see that ComplexPropertyGetOperationHandler has the following logic:

1. Expose $top, $skip, $search, $filter $count for a collection
2. Try to expose $select and $expand

On the contrary EdmOperationImportOperationHandler has the following logic:

1. Expose $top, $skip, $search, $filter $count for a collection
2. Expose $select and $expand if 1. is true

Therefore I can't get $select and $expand for Function or Operation. Is it something explicitly prohibited by OData?
How can I do this in a different way?

P.S. I think as a workaround I can make alternate key. But I don't see any examples for OData 8

Start with ComplexPropertyGetOperationHandler and EdmOperationImportOperationHandler, then reproduce the additional function registered on the XFax entity set. Compare the generated operations for entity-returning functions with the expected $select and $expand behavior. Done means confirming and correcting the handler behavior, with coverage for the reported case.