SplitQuery per-table definition

Currently (AFAIK) it's only possible to either have SingleQuery or SplitQuery defined globally for all queries, or per-query.
Would have been really helpful being able to set the default split query mode per table.
Consider a blogs -> posts relation, our blog has a logo column with max 4MB of data per row.
Joining the blog with its 10K posts can be devastating.

I think it should also be possible to set the mode by entity:

```
public class BlogConfiguration IEntityTypeConfiguration
{
public void Configure(EntityTypeBuilder builder)
{
builder.Property(entity => entity.Logo).HasMaxLength(1024 * 1024 * 4);
builder.WithSplitQuery(true);
}
}
```