Frontend Logging: Integrate grafana javascript agent (#50801)

Add Grafana Javascript Agent integration to Grafana

pkg/api/frontendlogging/grafana_javascript_agent.go

@@ -0,0 +1,28 @@
+package frontendlogging
+
+import (
+	"fmt"
+)
+
+type FrontendGrafanaJavascriptAgentEvent struct {
+	Exceptions   []Exception   `json:"exceptions,omitempty"`
+	Logs         []Log         `json:"logs,omitempty"`
+	Measurements []Measurement `json:"measurements,omitempty"`
+	Meta         Meta          `json:"meta,omitempty"`
+	Traces       *Traces       `json:"traces,omitempty"`
+}
+
+// KeyValToInterfaceMap converts KeyVal to map[string]interface
+func KeyValToInterfaceMap(kv *KeyVal) map[string]interface{} {
+	retv := make(map[string]interface{})
+	for el := kv.Oldest(); el != nil; el = el.Next() {
+		retv[fmt.Sprint(el.Key)] = el.Value
+	}
+	return retv
+}
+func (event *FrontendGrafanaJavascriptAgentEvent) AddMetaToContext(ctx CtxVector) []interface{} {
+	for k, v := range KeyValToInterfaceMap(event.Meta.KeyVal()) {
+		ctx = append(ctx, k, v)
+	}
+	return ctx
+}