feat: initializes otel metric collection for ftl dev and introduces a…

… couple shared otel metric attributes (#2140)

internal/observability/metrics/attributes.go

@@ -0,0 +1,18 @@
+package metrics
+
+import (
+	"github.com/TBD54566975/ftl/backend/schema"
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// ModuleNameAttribute identifies the name of the module that the associated
+// metric originates from.
+func ModuleNameAttribute(name string) attribute.KeyValue {
+	return attribute.String("ftl.module.name", name)
+}
+
+// VerbRefAttribute identifies the verb that the associated metric originates
+// from. The entire module qualified name is used: e.g. {module.verb}
+func VerbRefAttribute(ref schema.Ref) attribute.KeyValue {
+	return attribute.String("ftl.verb.ref", ref.Name)
+}