View work coordination

[pelikhan]

We finally have a proper webview to render the results of the scripts, as opposed to over-using the Markdown preview view in VSCode. This means that there's annoying things we can go fix like retaining the collapse state of details sections.

• local build instructions: https://github.com/microsoft/genaiscript/blob/main/CONTRIBUTING.md#web-viewer
• issues: https://github.com/microsoft/genaiscript/issues?q=state%3Aopen%20label%3A%22webview%22

Let's use this discussion to coordinate.

[pelikhan]

@volkanunsal