Refactor server code (#407)

internal/web/handlers/health/metrics.go

@@ -0,0 +1,9 @@
+package health
+
+import "github.com/thomiceli/opengist/internal/web/context"
+
+// Metrics is a dummy handler to satisfy the /metrics endpoint (for Prometheus, Openmetrics, etc.)
+// until we have a proper metrics endpoint
+func Metrics(ctx *context.Context) error {
+	return ctx.String(200, "")
+}