Resolve "The key for more complex paths in the map containing information of update events should be improved"

This MR changes the key for more complex paths (used within a subscribe event) from: qkd_node/qkd_links/qkd_link" key:{key:"qkdl_id" value:"acde2729-3544-41c3-88cb-9a9b82efeff0"/qkdl_status/ to /qkd_link[qkdl_id=acde2729-3544-41c3-88cb-9a9b82efeff0]/qkdl_status

Description

Using ygot.PathToString instead of our current own method for path to string parsing, results in a more manageable key within the event's pathAndValues map

Related Issue

#326

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

controller/nucleus/networkElementWatcher.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"strconv"
-	"strings"
 
 	"code.fbi.h-da.de/danet/gosdn/controller/customerrs"
 	"code.fbi.h-da.de/danet/gosdn/controller/event"
@@ -15,6 +14,7 @@ import (
 	"code.fbi.h-da.de/danet/gosdn/forks/goarista/gnmi"
 	"github.com/google/uuid"
 	gpb "github.com/openconfig/gnmi/proto/gnmi"
+	"github.com/openconfig/ygot/ygot"
 	log "github.com/sirupsen/logrus"
 )
 
@@ -184,13 +184,9 @@ func (n *NetworkElementWatcher) handleSubscribeResponseUpdate(resp *gpb.Subscrib
 	pathsAndValues := make(map[string]string, len(resp.Update.Update))
 
 	for _, update := range resp.Update.Update {
-		pathString := ""
-
-		// go through elem to build full path
-		for _, elem := range update.Path.Elem {
-			// remove unwanted parts of path string example: "name:\"system\"" -> "system"
-			filteredElem := elem.String()[strings.Index(elem.String(), ":\"")+2 : len(elem.String())-1]
-			pathString += filteredElem + "/"
+		pathString, err := ygot.PathToString(update.Path)
+		if err != nil {
+			log.Errorf("Error trying to create a string from path: %v", err)
 		}
 
 		pathsAndValues[pathString] = update.Val.GetStringVal()