Rework everything to access the prometheus-cpp objects more directly

src/telemetry/Utils.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <string_view>
+
+#include "zeek/Span.h"
+#include "zeek/Val.h"
+
+#include "prometheus/family.h"
+#include "prometheus/labels.h"
+
+namespace zeek::telemetry {
+
+using LabelView = std::pair<std::string_view, std::string_view>;
+
+namespace detail {
+
+/**
+ * Builds a set of labels for prometheus based on a set of labels from
+ * Zeek. This adds an 'endpoint' label if it's missing from the set.
+ */
+prometheus::Labels BuildPrometheusLabels(Span<const LabelView> labels);
+
+/**
+ * Builds a full metric name for Prometheus from prefix, name, and unit values.
+ */
+std::string BuildFullPrometheusName(std::string_view prefix, std::string_view name, std::string_view unit,
+                                    bool is_sum = false);
+
+} // namespace detail
+} // namespace zeek::telemetry