Publish messages with properties from a WindowFunction

### Search before asking

- [X] I searched in the [issues](https://github.com/apache/pulsar/issues) and found nothing similar.

### Motivation

When using a **_WindowFunction_** to publish messages to an output topic, the original properties of the input messages are not forwarded. Forwarding properties works for functions which process individual messages but it doesn't work for functions which process a collection of messages.

### Solution

A few possible solutions:

1. Enhance **_WindowContext_** to be able to publish properties together with properties.

Messages can be published to the output topic using the publish method of the **_WindowContext_** received as a parameter in **_WindowFunction.process_** method. Additional params could be added to the **_WindowContext.publish_** method to specify the properties to be included in the output message.

2. Enhance the function configuration parameters.

Additional configuration parameters can be added in the yaml function spec which could be used as properties for all messages published from the function.

3. Add the possibility to publish messages of type **_Message_** which already incorporate properties.

### Alternatives

_No response_

### Anything else?

_No response_

### Are you willing to submit a PR?

- [X] I'm willing to submit a PR!