Handle NewArrayExpression in entity equality

[roji]

Fixes #17744

@smitpatel the fix here is trivial/minimal to unblock the issue for 3.1: the EE visitor simply ignores (unwraps) entity reference node coming up from the NewArray's expressions.

A more complete fix would be to actually bubble this information up (probably all expressions must bubble up the same thing, or we start tracking information per element, like we do for anonymous objects). However, unless I'm mistaken, there's not actually much (anything?) that can be composed over this which EF Core can actually translate. For example, we don't support subscripting the array just created or anything similar, so there doesn't seem to be any value in this (right now).

Let me know if this sounds reasonable and if you'd like me to do something more on this.

[smitpatel]

Yes, we don't compose over it so we don't need to flow information out. At least for now. If you can think of any other Visit* method we need to override to make sure unwrapping is happening...

[roji]

Thanks.

I know that these bugs are cropping up every now and then because of yet another unhansled expression type (partially because of me still discovering the corners of the expression tree works). I will try to sit down for 3.1 and exhaustively go over all possible types and confirm that everything is handled (will open an issue tomorrow).