Filter symbol first before creating InheritanceMargin target

[Cosifne]

Fixes AB#1514769
The reason for the IndexOutOfRange exception is because there is no target for a given InheritanceMarginItem.
And it happens because

Code defects here
At all the similar places, it creates an InheritanceMarginItem when there are base type symbols or derived type symbols.
However, there is another filtering later, which is checking if the symbol could be navigable.
And if this filter gets all the symbols out, then we end up with an InheritanceMarginItem with no targets.
This really happens in cases like

public class B : C
{
}
#line hidden
public class C
{
}

here for B, C is a hidden place, so it would be filtered by this line And for B, it has an empty InheritanceMarginItem.

The fix is:

1. I did some code refactoring to make sure before InheritanceMarginItem is created, we should check the target items is not empty.
2. Hidden places should be included.

[CyrusNajmabadi]

Done with pass.

[Cosifne]

Tag @CyrusNajmabadi to have a second review

[CyrusNajmabadi]

Looks great!