Fix interface cleanup

[ljkiraly]

Description

The vfConfig structure deleted too early and the inject module can not find the information to delete the interface.
Debug printouts added in cases when interface is added or deleted.

Issue link

Related to: networkservicemesh/deployments-k8s#9778

How Has This Been Tested?

• Added unit testing to cover
• Tested manually
• Tested by integration testing
• Have not tested

Types of changes

• Bug fix
• New functionality
• Documentation
• Refactoring
• CI

[glazychev-art]

@ljkiraly
Nice catch!
Perhaps it would be better if we changed the calls order in inject?
For example, currently it works like:

{
        ...
	rv, err := next.Client(ctx).Close(ctx, conn, opts...)
	injectErr := move(ctx, conn, c.vfRefCountMap, &c.vfRefCountMutex, metadata.IsClient(c), true)
	...
}

But we can change it to

{
        ...
	injectErr := move(ctx, conn, c.vfRefCountMap, &c.vfRefCountMutex, metadata.IsClient(c), true)
        if injectErr!=nil {
        ...
        }
	rv, err := next.Client(ctx).Close(ctx, conn, opts...)
	...
}

(same for server, I think)
Because it would be nice if the same element controlled adding and removing from vfconfig (mechanisms/kernel).

[denis-tingaikin]

@ljkiraly I think it can be merged. Would you like to resolve comment #275 (comment) before merging?

[ljkiraly]

@ljkiraly I think it can be merged. Would you like to resolve comment #275 (comment) before merging?

@denis-tingaikin Yes, please do not merge this yet. The comment is valid and I am to test with the proposed modification.

[denis-tingaikin]

@ljkiraly Sure, all good

[ljkiraly]

This is also fixed in sdk-kernel by correction: networkservicemesh/sdk-kernel#618