nav2_util::get_node_options_default is dead code

[Aposhian]

Feature request

Feature description

get_node_options_default is not used anywhere in Nav2. It was misleading me by thinking those default settings were being applied everywhere, when they are actually applied nowhere.

Implementation considerations

Some users may be using nav2_util::get_node_options_default in their own code. I don't know how we sunset it without breaking people's code. Add a compile time deprecation warning?

[SteveMacenski]

Removed