Warning messaging

Working on [Updated Versioning](https://github.com/dylibso/observe-sdk/issues/143). I added deprecation warnings for the old namespace `dylibso_observe`. However, I'm not sure they are going the right place or actually making it to the observe-sdk user across the languages and adapters. We should decide on a consistently policy for this and apply it everywhere.

Currently, the rust sdk outputs with `log::warn!` and the basic example is setup to by default log with warnings.

The go-sdk outputs to the standard logger with `log.Println`.

The js-sdk outputs with `console.warn`.