feat: add isAsync and isAsterisk to function expressions and isOptional to ElementAccessExpr

[sam-goodwin]

Partial #374

We were missing the following information from our tree:

async function foo() { }
function *foo() {}
async function *foo() {}

class Foo {
  async foo() { }
 *foo() {}
  async *foo() {}
}

object?.[element]
        // ^ 

[netlify]

✅ Deploy Preview for effortless-malabi-1c3e77 ready!

Name	Link
🔨 Latest commit	c793f30
🔍 Latest deploy log	https://app.netlify.com/sites/effortless-malabi-1c3e77/deploys/62eb2dee8e3f1f00088116a9
😎 Deploy Preview	https://deploy-preview-382--effortless-malabi-1c3e77.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.