The message writing logic is coupled withduplicated in the `CSseederNode` class for no reason.. Using the same code as the node
Refactoring the seeder's message writing code to use the same code as the node
software makes the code easier to test and maintain. This also makes it easier to
add more types of messages that the seeder can sendmakes it easier to test, maintain, and add new message types for the seeder to support.
Depends on D6355 and D8622