Remove the internal name again and pick the first exported one when
assigning ids. This avoids internal names showing up in code completion
or the internal types leaking into generated code.
When exporting an global multiple times under different names, make sure
that they alias in the generated code.
As a consequence, the compiler maintains the original unique name and in
Rust and C++ makes only the exported names public. In the interpreter
the internal name is theoretically still accessible from the outside.
As a result
- The error messages will now show the error with `-` instead of `_`
- The LSP will auto-complete with -
- The interpreter's list of properties will list the property with '-'
(but we made the change so that set_property, get_property, and so on
work also if passed a '-')
