Pass logs through to Amethyst logger

Currently `EditorLogger` only passes log output to the editor, but doesn't log anything to the local console. It would be good to also be able to pass log output through the regular Amethyst logger in order to be able to still see log output when the editor isn't running. This is especially important currently since no editor front end handles displaying log output well.

Amethyst exposes the [`Logger`](https://www.amethyst.rs/doc/latest/doc/amethyst/struct.Logger.html) type as the concrete logger implementation, as well as the [`LoggerConfig`](https://www.amethyst.rs/doc/latest/doc/amethyst/struct.LoggerConfig.html) for configuring the logger. `EditorLogger` should be updated to take a `LoggerConfig` as an optional parameter, and should forward any log output to an internal Amethyst `Logger` if configured to do so. This can likely take the form of an additional method `EditorLogger::forward_logs(config: LoggerConfig)`.