Add race(...commandList) and all(...commandList) commands

They should work exactly how Promise.all and Promise.race works but for commands.

```ts
const payloadOrVoid = yield ctx.race([ctx.sleep(10 *Second), ctx.waitForSignal("sms_response")]
```
This should be modeled as a single command that contains two commands in it. Similarly, a single event should contain execution of both commands.