Extern examples

[PXshadow]

Adds a new folder examples in root to show how to use extern Go libraries in Haxe, and to run in CI to prevent regressions.

We also might want to add net/http and other useful Go stdlib examples.

I also think we shouldn't add everything under the sun into examples the criteria should either be as a regression test for a previously failing extern library or useful for Haxe devs + widely used.

Off the top of my head what would be great additions would be:

• bubbletea (terminal user interface)
• goja (javascript engine in pure Go)
• harmonica (physics based animations)
• tetra3d (we made a game in it haha)
• mysql
• pion (webrtc)
• wazero (zero dep wasm runtime)
• esbuild (js bundler with Go api)
• zap (structured logging)
• nats (messaging system similar to elixir)
• pgx (postgress support)
• go-echarts (chart support, we use this for our Haxe unit test chart)
• opencv (computer vision)
• gopdf (pdf generation)
• go-humanize (human readable number generation)
• chroma (syntax highlighting)
• mpb (multi progress bar)

[PXshadow]

Bubble tea requires us to support Go type switching, we need to add support similarly how we did Syntax.select.