the timestamp offset support for consumer

[louie7]

Is your feature request related to a problem? Please describe.

as RabbitMQ doc, https://www.rabbitmq.com/docs/streams
This is controlled by the x-stream-offset consumer argument. If it is unspecified the consumer will start reading from the next offset written to the log after the consumer starts. The following values are supported:

Could this python client support this feature?

Thanks,

Louie

Describe the solution you'd like

provide timestamp support in offset_specification

Describe alternatives you've considered

No response

Additional context

No response

[Gsantomaggio]

Thank you, @louie7, for raising the issue. Feel free to propose a PR; otherwise, I will have a look once I get back from holidays! 🛫