Answer:
Yes, Canada is a nation of both peacekeepers and peacemakers.
No, peacekeeping is not a myth.
Step-by-step explanation:
Peacekeepers country often put itself in a position as mediators between other countries that interacted with one another. Canada has done this several times throughout history (one small example would be when Canada mediate a conflict of imports quota between United States and Mexico).
On top of that, Canada also involved in several peacemakers mission when they sent their resources to help the people who are trapped within political conflicts. (one example of this would be when Canada sent help to Cambodia during four peace support missions from 1954 to 2000.)
From those historical events alone, I believe Canada could be considered as a nation of both peacekeepers and peacemakers.