Variable name in Notification request is different from ETSI definition

[Wataru Juso]

# Problem
The resource variable name in the notification request is incorrect of a few operation.

* Correct
    "affectedVnfcs": [
        {
            "id": "882e4f9e-13c6-4e6b-92a0-527985daacca",
            "vduId": "VDU1",
            "changeType": "ADDED",
            "computeResource": {

# Incorrect
    "affectedVnfcs": [
        {
            "id": "c6fea56b-7b17-47f1-ad20-38fe40ed5dbe",
            "vdu_id": "VDU1",
            "change_type": "ADDED",
            "compute_resource": {

# Affected
There is a possibility that the receiver will not be able to process the data.

# Expected behavior:
The variable name of the Notification request data needs to be changed from snake case to camel case at sending time.

[Wataru Juso (w-juso)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/tacker/+/774238

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/tacker 5.0.0.0rc1 release candidate.