Resolve "Refactor how PNDs are implemented in the code"

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

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.

Closes #243

controller/northbound/server/nbi.go

@@ -52,7 +52,7 @@ func NewNBI(
 	networkDomain networkdomain.NetworkDomain,
 ) *NorthboundInterface {
 	return &NorthboundInterface{
-		Pnd:            NewPndServer(pndService),
+		Pnd:            NewPndServer(pndService, sbiService),
 		Core:           NewCoreServer(pndService),
 		Csbi:           NewCsbiServer(pnds),
 		Sbi:            NewSbiServer(pndService),