[UI/Core Split] Split the Utilities in place into CoreUtilities.cs & WinFormsUtilities.cs

[benfleuty]

Due to issues with circular dependencies when creating a second project, we need to split up the codebase as much as we can within the one project.

This issue aims to split Utilities.cs into its two separate concerns: Core & WinForms.

[soda3x]

I assume the models are not considered UI which is the point of them

[benfleuty]

Yes, models will move into the core. Currently, it's not easy to do this.

Take Mod for example. WinForms would have a dep. on Core to use it if we moved it. However, to move it, we also need to move ToolPropertiesManager as Core cannot depend on WinForms for it. There's some refactoring to do to decouple things a bit more before we move to multpile projects.

If we move Mod, we move ToolPropertiesManager, which means we move ToolProperties. Quite the domino effect with some of these, and I'd like to avoid massive PRs as much as is feasible with this work.

[soda3x]

Yep sounds good. I'm understanding.

[Henry-Cahill]

Please let me know how I can help! I think moving to a core and WinUI structure is the best idea