IDE0058 and null propagation - Inconsistent, request fix.

[UniqeId6542]

class Data { public bool Value { get; set; } }

void Foo(Data? data)
{
    data!.Value = true; // OK
    bool b1 = data!.Value = true; // OK
    _ = data!.Value = true; // OK
    data?.Value = true; // IDE0058
    bool? b2 = data?.Value = true; // OK
    _ = data?.Value = true; // OK
}

For null conditional assignments, I'd like it to NOT produce IDE0058 - the same as normal assignments.

I have IDE0058 set to make a warning so as to avoid missed data from method returns. But I don't want to have to "handle" the data from a null conditional assignment. And, I notice that normal assignments don't produce this message even though they also have a form of data return from the expression.

[333fred]

Converted to #80766.