OperatorID: Make OPERATOR ID messages optional

[muramura]

The Operator ID message is optional.

1. if the number of text characters is 0, the message is not sent.
2. Operator ID information can be set in the configuration parameter.

TEXT LEN > 0

TEXT LEN < 1

[tridge]

same Q as for the Self-ID PR. Should we add the complexity of not sending or just send blank like we do now?
the spec is vague about which jurisdictions require this message

[friissoren]

the spec is vague about which jurisdictions require this message

The operator ID is only mandatory in the EU. The rules and additional documents for the US and Japan specify the operator ID as optional. Whether any other jurisdiction will make it mandatory can only be speculated upon at this point.

[BluemarkInnovations]

In my opinion you should not broadcast packets with empty data. This saves energy and reduces co-existence issues.

[tridge]

@muramura @BluemarkInnovations I think this is handled in #101 ?