Part of #36296

Description

This fixes queries which involve structural containment for complex JSON collections:

var post = ...;
var blogs = context.Blogs.Where(b => b.Posts.Contains(post)).ToListAsync();

This sort of query currently fails when b.Posts is mapped as complex JSON. Making this work properly is part of the complex type/JSON push in 10.

Customer impact

All queries of the above form currently fail.

How found

Testing.

Regression

No

Testing

Tests added

Risk

Low, the fix almost exclusively touches new complex type/JSON code that was added in 10.