Describe the bug
Calling .ToQueryDefinition() throws an ArgumentNullException with message Value cannot be null. (Parameter 'sqlQuery') if a Where clause hasn't been added to the LINQ query.

The string representation of the IOrderedQueryable is the url path to the Container.

If I set a dummy lambda (.Where(q => true)) the query works.

To Reproduce

new CosmosClient("...connection string here...")
    .GetDatabase("AAA")
    .GetContainer("BBB")
    .GetItemLinqQueryable<Test>()
    .ToQueryDefinition();

Expected behavior
The query will return the Items in the Container.

Actual behavior
An ArgumentNullException is thrown.

Environment summary
SDK Version: 3.6.0 and 3.8.0
OS Version: Windows 10, Visual Studio Professional 2019 16.5.3

Additional context
Was previously reported and closed as Resolved: #719