GDScript: Fix Inspector "Add Input" button, improve tweening, add print in chat, fix entry signals, add export vars

First commit: Improve tweening and add print in chat

Second commit: Fix Inspector "Add Input" button

It used to be hard-coded for visual scripting in the inspector, now there is a method create_inspector_paramter_input that is overridden for GDScript and visual scripting separately.
Previously the GDScript code only did a trivial signal connection, now there is a new method connect_entry_signal that can handle the case of connecting the signal with bindings.
New helper method set_inspector_parameter_input_value (no functionality change).
Also thrown in: Update the script template comment to encourage Notify.info instead of print.

Third commit: Fix custom entry signal creation dialog.

Fourth commit: Sync exposed @export vars with SpaceObject space vars

Now @export vars are saved as space vars, and space vars with a name matching the @export var are loaded in.
To update the var, thing = myvalue won't work, instead one of these options must be used:
- set_object_variable(thing, myvalue)
- thing = myvalue followed by save_exposed_vars.emit() (plus there is also load_exposed_vars.emit() if you want to read the space vars back into the script vars, this might be useful for sharing data between scripts).
In both cases, both the thing script var and the thing space variable on the object are updated. Users can use whatever workflow they prefer.

Fifth commit: Add a UI for updating export vars.

the-mirror-gdp / the-mirror