fix(Observe): missing traces in Mlflow

[GALLLASMILAN]

We need to call the forcePush method on the BatchSpanProcessor for each trace. Otherwise, this default processor skips some traces and doesn't send them to the OTLP server.

I added a new isOpenTelemetryEnabled variable, that allows the telemetry only for production environment:

export const isOpenTelemetryEnabled = Boolean(process.env.NODE_ENV === 'production');

Closes: i-am-bee/bee-observe#24

[jezekra1]

Is this necessary? I got the impression that opentelemetry should quietly work outside of your code and flush regularly on its own