Support for `util.inspect` and `util.inspect.custom`

[nabetti1720]

From what I've observed, some packages on @opentelemetry are built on the premise of util.inspect.

• @opentelemetry/resources
• @opentelemetry/sdk-metrics
• @opentelemetry/sdk-trace-base
• @opentelemetry/resource-detector-aws
• @opentelemetry/resource-detector-container

To avoid any misunderstanding, I believe that the components necessary for implementation already exist in llrt_logging, and simply implementing the following in the util module will work.

However, it completely ignores the options, so the output is not what you expect.

fn inspect<'js>(ctx: Ctx<'js>, args: Rest<Value<'js>>) -> Result<String> {
    let mut result = String::new();
    let mut options = llrt_logging::FormatOptions::new(&ctx, false, true)?;
    llrt_logging::build_formatted_string(&mut result, &ctx, args, &mut options)?;
    result.push(NEWLINE);
    Ok(result)
}

impl ModuleDef for UtilModule {
    // ...
    fn evaluate<'js>(ctx: &Ctx<'js>, exports: &Exports<'js>) -> Result<()> {
        export_default(ctx, exports, |default| {
            let globals = ctx.globals();
            // ...
            let inspect_fn = Function::new(ctx.clone(), inspect)?.with_name("inspect")?;
            inspect_fn.prop("custom", primordials.symbol_custom_inspect.clone())?;
            default.set("inspect", inspect_fn)?;
            Ok(())
        })
    }
}

I find it difficult to support the util.inspect options without breaking the existing llrt_logging implementation, so I hope that someone knowledgeable will take on the challenge of implementing it. :)