Studio molecules in scene buttons shift when text disappears

[KatieWoe]

For phetsims/qa#508, but seems to be SOM rather than studio.
When using the visible property to remove the text that is on the buttons to change scenes, the molecule image shifts a bit when the text disappears.

[jbphet]

@arouinfar - please weigh in and let me know if you think this is something that should be addressed and, if so, if it is blocking for the initial dev release to the customer.

[arouinfar]

@jbphet this is not critical to fix for the initial dev release. I wonder if this could be related to the dynamic layout when UI elements are removed. If I change the textProperty of the string to null, the layout is undisturbed.

[arouinfar]

Actually, on second thought, I think the current behavior is fine.

The gif shows what happens when the visibleProperty of the string (e.g. argonText) is set to false. This is not featured, and there are other ways to hide this text. If the goal is to remove the entire radio button, then the visibleProperty of the radio button should be set to false. If the goal is to hide the name, its textProperty can be edited to be a null string. Neither of these methods cause layout issues.

@jbphet please feel free to close if you agree.

[jbphet]

Thanks. I do agree. Closing.