Query: add support for correlated collection optimization for queries with GroupBy

[maumar]

Currently, if query contains group by on the top level, correlated collection optimizations won't be applied - we will still produce N+1 queries.

example:

ctx.Gears.Select(g => new { g.Rank, g.Weapons }).GroupBy(g => g.Rank).ToList();

produces:

            AssertSql(
                @"SELECT [g].[Rank], [g].[FullName]
FROM [Gears] AS [g]
WHERE [g].[Discriminator] IN (N'Officer', N'Gear')
ORDER BY [g].[Rank]",
                //
                @"@_outer_FullName1='Augustus Cole' (Size = 450)

SELECT [w0].[Id], [w0].[AmmunitionType], [w0].[IsAutomatic], [w0].[Name], [w0].[OwnerFullName], [w0].[SynergyWithId]
FROM [Weapons] AS [w0]
WHERE @_outer_FullName1 = [w0].[OwnerFullName]",
                //
                @"@_outer_FullName1='Garron Paduk' (Size = 450)

SELECT [w0].[Id], [w0].[AmmunitionType], [w0].[IsAutomatic], [w0].[Name], [w0].[OwnerFullName], [w0].[SynergyWithId]
FROM [Weapons] AS [w0]
WHERE @_outer_FullName1 = [w0].[OwnerFullName]",
                //
                @"@_outer_FullName1='Damon Baird' (Size = 450)

SELECT [w0].[Id], [w0].[AmmunitionType], [w0].[IsAutomatic], [w0].[Name], [w0].[OwnerFullName], [w0].[SynergyWithId]
FROM [Weapons] AS [w0]
WHERE @_outer_FullName1 = [w0].[OwnerFullName]",
                //
                @"@_outer_FullName1='Dominic Santiago' (Size = 450)

SELECT [w0].[Id], [w0].[AmmunitionType], [w0].[IsAutomatic], [w0].[Name], [w0].[OwnerFullName], [w0].[SynergyWithId]
FROM [Weapons] AS [w0]
WHERE @_outer_FullName1 = [w0].[OwnerFullName]",
                //
                @"@_outer_FullName1='Marcus Fenix' (Size = 450)

SELECT [w0].[Id], [w0].[AmmunitionType], [w0].[IsAutomatic], [w0].[Name], [w0].[OwnerFullName], [w0].[SynergyWithId]
FROM [Weapons] AS [w0]
WHERE @_outer_FullName1 = [w0].[OwnerFullName]");

[smitpatel]

Not needed. We don't have correlated collection "optimization" anymore.
Linking to client group by issue #17068