[release/7.0] Query: Don't fail translation of aggregate when owned navigations

[smitpatel]

Resolves #29201

Description

Regression in a relatively important case where aggregate functions are used over owned type mapped to the same table as the owner. For example:

var query = context.Books
    .GroupBy(post => post.Author.Id)
    .Select(grouping => new
    {
        Author = grouping.Key,
        TotalCost = grouping.Sum(post => post.Detail.Price),
    });

This was due to a significant change in the design for aggregate functions, enabling a lot of new functionality in EF7. We were missing test cases for this.

Customer impact

Exception in a relatively common query case that worked in EF Core 6.0.

How found

Found writing docs for new features.

Regression

Yes. from 6.0.

Testing

New testing added; will also investigate additional testing in this area.

Risk

Low, since the test removes an incorrect check when looking for errors.