This commit changes how NanoUI's live data updating system works.
Previously, data for the template was directly gathered in the
ui_interact proc. Now, it is seperated into the proc `ui_data`.
To players, this does absolutely nothing.
To coders, this opens up the potential for a much more complicated and
fancy graphical updating system in the future, because the data is
available on-demand without ever having to call
nanomanager.try_update_ui.
Currently, to_chat is literally just a proc that does user << message.
But it'll let us do output modification in the future, especially for
something like Goon's HTML chat.
Big thanks to PJB for his to_chat script, see
https://github.com/d3athrow/vgstation13/pull/6625 for more details.
