Fix binding generation special cases

[JulioDRF]

Fixes #1901

These changes prevent binding.GenerateModels() from yielding broken TypeScript for the following special cases:

• Struct fields of imported types that also use imported types don't create a namespace for the nested type (it's messy to explain, see the binding_nestedimport_test)
• Struct fields of type []T or map[any]T where T is an imported struct don't reference the imported namespace in the generated code (e.g. we get foo: Foo[] instead of foo: imported.Foo[])
• Struct fields with non-standard JS variable names (e.g. `` Foobar string json:"foo-bar")
• Struct fields of type map[T]any (where T is anything but string)

And finally:

• Added tests for all of the above

Extra notes:

I necromanced the binding tests from https://github.com/wailsapp/wails/tree/feature/ts-generation-tests and expanded upon them. I see that the branch has since been deleted, and the directory structure for the tests in this PR feels inelegant, so let me know if there's an obvious way to improve it and I will revise it.

As far as I can tell, the new tests cover these issues and they are resolved

• TS model from mixed package struct don't generated #1444
• binding / typescriptify: nested structs are not "known" #1476
• Unable to infer types of sub backend packages and some golang data types in wailsjs models.d.ts generation #1772

[leaanthony]

This is amazing! Thank you so much for taking the time and effort to look into this important area. It would be good to get feedback from those who opened the linked issues and see what the feedback is. Other than that, it looks great!

[leaanthony]

I think we can go with this. Thank you so much 🙏