add batch scheduler implementation for Godot

[nadako]

I continue toying with Godot (see #17), so here's an implementation of a batch scheduler that hooks into Godot frame loop.

You're supposed to reference Nadako.TinkState and Nadako.TinkState.Godot assemblies in your C# project and add the TinkStateBatchScheduler script to AutoLoads.

I have yet to learn how to make the setup process easier here. Maybe make NuGet packages for the DLLs and a Godot Asset Library asset for the script? Not sure, will ask around...

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (d5e7e48) 99.15% compared to head (2202b84) 99.15%.

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Additional details and impacted files

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