Move `GSE` and `SMV` between `ConnectedAP`

[JakobVogelsang]

Is your feature request related to a problem? Please describe.
As a user of OpenSCD I want to move a GSE or SMV element between different ConnectedAP element of the same IED.

The communication related settings of a GOOSE control block are saved within the GSE element in the Communication section and here in the parent ConnectedAP. As such, a GOOSE is linked to an access point of an IED. This is used by some vendors to scross check if a link - GOOSE data to input - does make sense.

At the moment when creating a GOOSE we add the GSE we add it the ConnectedAP that is linked with the server, which works for most of the users, but some need to move the GSE and SMV elements between different ConnectedAP of the same IED.

Describe the solution you'd like
I want to navigate to the communication plugin and click on a GSE or SMV element and move it to another ConnectedAP element of the same IED.

Requirements

• add a button to the GSE/SVM element representation in the communication plugin
• on button click give the user the choice of all other ConnectedAP element of the same IED
• disable the new button in case of:
  • an IED has only one AccessPoint and therefore only one ConnectedAP
  • an IED has multiple AccessPoints but only on ConnectedAP (only one access point it linkt to a subnetwork)

Additional information

• Mockups

[Sander3003]

Maybe you can add an example UI? Wireframe?

[Sander3003]

Looks good to me!

[Sander3003]

@salvar3nga please assign yourself to this issue

[salvar3nga]

a PR can be found here: com-pas/oscd-official-plugins#4

Only to be merged once the plugin extraction PR is fully completed on OpenSCD

[michelguerin]

@clepski will review this PR.