License environment variable is inconsistent with the rest of the Particular platform

[PhilBastian]

Describe the suggested improvement

Is your improvement related to a problem? Please describe.

The environment variable to store the license string for AWS Lambda (and other cloud platforms) is NSERVICEBUS_LICENSE. This differs from the main PARTICULARSOFTWARE_LICENSE variable used by Core and other desktop-based packages in the platform. This doesn't affect production deployment, but it does mean that the development experience requires two variables to be set if the developer is also working with other parts of the platform.

Describe the suggested solution

Deprecate NSERVICEBUS_LICENSE for this package in favour of PARTICULARSOFTWARE_LICENSE

Describe alternatives you've considered

None

related issues Particular/NServiceBus.AzureFunctions.Worker.ServiceBus#529 and Particular/NServiceBus.AzureFunctions.InProcess.ServiceBus#826

Additional Context

No response

[tmasternak]

The fact that AWS provides read-only access to the filesystem, means that AWS Lambda users can't take advantage of the trial license experience i.e. we can't generate a trial license for them on the first run of and endpoint. More context: https://discuss.particular.net/t/aws-lambda-failed-to-initialize-the-license/4027