1. Proposed title of this feature request

NMState Operator - add support for vlan-egress-priority-map configuration

2. What is the nature and description of the request?
Customer would like to have the option to configure the vlan-egress-priority-map setting using the nmstate operator

3. Why does the customer need this? (List the business requirements here)
Per customer comment:
> we need it to be configurable as part of NMState Operator when we create the vlan using NodeNetworkConfigurationPolicy.

4. List any affected packages or components.

OCP Version:              4.14.26
Nmstate version:          2.2.27
Nmstate operator version: kubernetes-nmstate-operator.4.14.0-202407101709