[Feature] Retrieve complex properties of derived types

[irvinesunday]

We need to generate complex properties of derived types (besides the navigation properties as we currently do).

We'll need to update this code block to achieve this:

OpenAPI.NET.OData/src/Microsoft.OpenApi.OData.Reader/Edm/ODataPathProvider.cs

Lines 690 to 701 in 2a48a30

	if (convertSettings.ExpandDerivedTypesNavigationProperties)
	{
	if (annotable is IEdmNavigationProperty navigationProperty && !navigationProperty.ContainsTarget)
	{
	continue;
	}
	foreach (var declaredNavigationProperty in targetType.NavigationProperties())
	{
	RetrieveNavigationPropertyPaths(declaredNavigationProperty, null, castPath, convertSettings);
	}
	}

to something like...

if (convertSettings.ExpandDerivedTypesNavigationProperties)
{
    if (annotable is IEdmNavigationProperty navigationProperty && !navigationProperty.ContainsTarget)
    {
        continue;
    }

    foreach (var declaredNavigationProperty in targetType.NavigationProperties())
    {
        RetrieveNavigationPropertyPaths(declaredNavigationProperty, null, castPath, convertSettings);
    }
    
    if (targetType is IEdmEntityType entityType)
    {
        RetrieveComplexPropertyPaths(entityType, castPath, convertSettings);
    }                                                
}

Thoughts: Should we add a new convert setting named RetrieveDerivedTypesProperties and deprecate ExpandDerivedTypesNavigationProperties. This will account for retrieving both complex and navigation properties of derived types.

Related to: microsoftgraph/msgraph-metadata#465 (this feature is required for the mentioned issue to be achieved)