Feature parity: Add IQueryTypeConfiguration<TEntity>

[ilmax]

I really like the addition of the new IEntityTypeConfiguration<TEntity> type that allows us self-contained type configuration for code first and if I'm not missing anything, this types allows only entity (i.e. not query types) to be configured.
I think ef can provide the same experience for query types as well so I propose adding a new IQueryTypeConfiguration<TEntity> with this shape:

public interface IQueryTypeConfiguration<TEntity>
   where TEntity : class
{
     void Configure(QueryTypeBuilder<TEntity> builder);
}

as well as a new ApplyConfiguration overload on the ModelBuilder class like the following:

public virtual ModelBuilder ApplyConfiguration<TEntity>([NotNull] IQueryTypeConfiguration<TEntity> configuration)
   where TEntity : class
{
   // implementation omitted
}

allowing us to write configuration for entity types and query types in a consistent way.

[ilmax]

if you guys like the idea and label it as an up for grabs/are interested in a contribution for this one, I can submit a PR

[ajcvickers]

@ilmax We would love a PR to fix this one. Thanks!