ProcessingScheduleService allows to schedule a task which returns a Result

[Zelldon]

Description

We started to introduce the new ProcessingScheduleService still the consumers of this service use the LogStreamWriter, which they get from the Engine/StreamProcessorContext.

Ideally the consumers of the Service can just schedule a Task, which returns an Result. The result should be written to the Log (internally in the streamProcessor). The consumer of the service doesn't care how this is done, and doesn't need to know about LogStreamWriters.

What we need:

• Introduce a ProcessingScheduleResult
  • potentially backed by similar implementation (parts) of the other ProcessingResult
• New methods to schedule a Task which returns an result
• Implementation of that
• Backened in the StreamProcessor, like writing the result to the logstream
• We need to make sure that the scheduling is guaranteed to happen only during processing not in between and after a committed transaction
• During pause no execution should happen
• We need tests

related to #9730

[Zelldon]

Partly done via #10076 rest is via #10012