logging in `@std/log` should be async

[justinmchase]

Is your feature request related to a problem? Please describe.

I want to make a logger that pushes logs into a network api but I don't see how its possible with this api.

Describe the solution you'd like

The BaseLogger.log method would need to be async. All methods to log would be promise based.

await logger.info("for example");

Describe alternatives you've considered

Implementing a completely parallel logging system.

[kt3k]

I want to make a logger that pushes logs into a network api but I don't see how its possible with this api.

You can handle logs asynchronously in the handler implementation. You don't need to return the promise of network requests.