Add stream health overview collection + apis

models/streamHealth.go

@@ -0,0 +1,8 @@
+package models
+
+// StreamHealthOverview represents an overview of the current stream health.
+type StreamHealthOverview struct {
+	Healthy           bool   `json:"healthy"`
+	HealthyPercentage int    `json:"healthPercentage"`
+	Message           string `json:"message"`
+}