Refactor publishNextPost to reduce code duplication

[fernand0]

The publishNextPost method has common logic that is repeated in several modules. This logic
should be extracted into a generic method in moduleContent. The individual modules should
then only contain the code that is specific to their implementation.

Tasks:

• Identify the common logic in the publishNextPost methods.
• Create a generic publishNextPost method in moduleContent with the common logic.
• Refactor the publishNextPost methods in the individual modules to use the new generic
  method.