fix: prepend port with node name, to prevent "duplicate ports" error in multi-node clusters

[acch]

Fixes #409.

When adding VLAN(s) to a broadcast domain, the broadcast domain will contain a list of ports added to it. In multi-node clusters, the same port/VLAN may exist on multiple nodes. With the current implementation, this will lead to the following error message:

╷
│ Error: Duplicate Set Element
│ 
│   with module.netapp.module.network.netapp-ontap_network_broadcast_domain.this,
│   on ../../modules/network/main.tf line 12, in resource "netapp-ontap_network_broadcast_domain" "this":
│   12: resource "netapp-ontap_network_broadcast_domain" "this" {
│ 
│ This attribute contains duplicate values of: tftypes.String<"a0a-1234">
╵

This PR changes the code in a way that the port name is prefixed with the node name - in order to make the string values unique. This mimics the behavior of the CLI, which also prepends the node name to the port name in the output of broadcast-domain show.

Acceptance tests (still) pass in my local test setup:

$ TF_ACC=1 go test ./internal/provider/networking/network_broadcast_domain_resource_test.go -v
=== RUN   TestAccNetworkBroadcastDomainResource
--- PASS: TestAccNetworkBroadcastDomainResource (3.72s)
PASS
ok      command-line-arguments  3.731s

[acch]

@carchi8py @suhasbshekar Unfortunately, I've missed this bug in my local test setup (single-node cluster). It has only surfaced while integrating the new provider version into the customer's staging environment (multi-node cluster). It's now blocking our integration efforts, preventing us to continue migration to the official provider...

Any chance to merge this PR and release a new version to the registry short-term?

[acch]

@carchi8py @suhasbshekar Any chance to merge & release this fix short-term?