Designate DNS – list shared zones API (using Admin) responds with 200 OK for non-existing zone/project ID

### Scenario ###
List shared zones using invalid zone ID, here is it:
@decorators.idempotent_id('871e7e1c-bd9a-11ed-80f5-201e8823901f')
def test_list_zone_shares_invalid_zone_id(self):
    LOG.info(
        'Admin user lists shared zone using not existing zone ID')
    sudo_header = {
        'x-auth-sudo-project-id': self.share_zone_client.project_id}
    self.assertRaises(lib_exc.NotFound,
       lambda: self.adm_shr_client.list_zone_shares(
           dns_data_utils.rand_uuid(), headers=sudo_header))

To reproduce the scenario you can use this test patch:
1) test_list_zone_shares_invalid_zone_id
https://review.opendev.org/c/openstack/designate-tempest-plugin/+/875919/7/designate_tempest_plugin/tests/api/v2/test_shared_zones.py#488

2) test_list_zone_shares_invalid_project_id
https://review.opendev.org/c/openstack/designate-tempest-plugin/+/875919/7/designate_tempest_plugin/tests/api/v2/test_shared_zones.py#499

### Actual Result ###
API responds with 200 OK + empty list for shared_zones, like this:
2023-03-08 10:31:04.536 560986 INFO tempest.lib.common.rest_client [req-a44bcf7f-3112-448c-bccb- 200 GET https://192.168.122.49/dns/v2/ 0.025s
2023-03-08 10:31:04.537 560986 DEBUG tempest.lib.common.rest_client [req-a44bcf7f-3112-448c-bccb-
        Body: None
    Response - Headers: {'date': 'Wed, 08 Mar 2023 10:31:04 GMT', 'server': 'Apache/2.4.41 (Ubuntu)', 'content-length': '119', 'content-type': 'application/json', 'x-openstack-request-id': 'req-a44bcf7f-3112-448c-bccb-https://192.168.122.49/dns/'}
        Body: b'{"shared_zones": [], "links": {"self": "https://127.0.0.1:60053/v2/"}}' _log_request_full /opt/stack/tempest/tempest/

### Expected result ###
If zone ID doesn’t exists in Designate DB, responding with “404 NotFound" (instead of 200 OK and empty list) could have make sense.

### Note ###
Existing zones list API has the same behavior:

REQ: curl -g -i -X GET http://10.21.21.126/dns/v2/ -H "Accept: application/json" -H "Content-Type: application/json" -H "User-Agent: python-designateclient-5.2.0" -H "X-Auth-Token: {SHA256}
Resetting dropped connection: 10.21.21.126
http://10.21.21.126:80 "GET /dns/v2/zones?name=bogus HTTP/1.1" 200 110
RESP: [200] Connection: close Content-Length: 110 Content-Type: application/json Date: Wed, 08 Mar 2023 21:28:41 GMT Server: Apache/2.4.52 (Ubuntu) x-openstack-request-id: req-0be38914-14f8-45da-81a8-
RESP BODY: {"zones": [], "links": {"self": "http://127.0.0.1:60053/v2/"}, "metadata": {"total_count": 0}}

This means that will need to fix Zone API and maybe some other APIs that have a similar behavior.