Integration tests are not stable after adding OPA policy for registry feature

[NikitaSkrynnik]

Description

Heal tests with nsmgr restart are not stable. When we are deleting old nsmgr, it doesn't unregister its forwarder from registry. New nsmgr (with new spiffeID) can't register this forwarder again, because it's already registered by old nsmgr (with old spiffeID).

How to reproduce

1. Run basic nsm setup
2. Delete one of NSMGRs
3. Wait for new NSMGR start
4. See logs in registry pod

Expected behavior

NSMGR registers its forwarder successfully

Actual behavior

NSMGR can't register its forwarder, because it's already registered by old deleted nsmgr

[TRAC] [type:registry] (2.1)    register={"name":"forwarder-vpp-6tpfn","network_service_names":["forwarder"],"network_service_labels":{"forwarder":{"labels":{"nodeName":"kind-worker","p2p":"true"}}},"url":"tcp://10.244.1.109:5001","expiration_time":{"seconds":1663668686,"nanos":268959800},"initial_registration_time":{"seconds":1663668484,"nanos":824354244}}
[INFO] [type:registry] (2.2)    AUTHORIZE spiffieIDNSEsMap: map[spiffe://example.org/ns/nsm-system/pod/nsmgr-h7h5k:[forwarder-vpp-x565x nse-kernel-56c9ffbff5-bwpvs] spiffe://example.org/ns/nsm-system/pod/nsmgr-tcx5p:[forwarder-vpp-6tpfn]]
[INFO] [type:registry] (2.3)    AUTHORIZE spiffieID: spiffe://example.org/ns/nsm-system/pod/nsmgr-tkc59
[INFO] [type:registry] (2.4)    AUTHORIZE nseName: forwarder-vpp-6tpfn
[ERRO] [type:registry] (2.5)    rpc error: code = PermissionDenied desc = no sufficient privileges;	Error returned from sdk/pkg/registry/common/authorize/authorizeNSEServer.Register;	github.com/networkservicemesh/sdk/pkg/registry/core/trace.logError;		/build/local/sdk/pkg/registry/core/trace/common.go:38;	github.com/networkservicemesh/sdk/pkg/registry/core/trace.(*traceNetworkServiceEndpointRegistryServer).Register;		/build/local/sdk/pkg/registry/core/trace/nse_registry.go:129;	github.com/networkservicemesh/sdk/pkg/registry/core/next.(*nextNetworkServiceEndpointRegistryServer).Register;		/build/local/sdk/pkg/registry/core/next/nse_registry_server.go:59;	github.com/networkservicemesh/sdk/pkg/registry/common/begin.(*beginNSEServer).Register.func2;		/build/local/sdk/pkg/registry/common/begin/nse_server.go:64;	github.com/edwarnicke/serialize.(*Executor).process;		/go/pkg/mod/github.com/edwarnicke/serialize@v1.0.7/serialize.go:68;	runtime.goexit;		/usr/local/go/src/runtime/asm_amd64.s:1571;	
[ERRO] [type:registry] (1.2)   Error returned from sdk/pkg/registry/common/authorize/authorizeNSEServer.Register: rpc error: code = PermissionDenied desc = no sufficient privileges

Possible solultions

1. Wait until forwarder entry in registry is expired
2. Add feature for heal servers: immediately delete entry from registry if the connection with endpoint is lost
3. Disable OPA authorization for cmd-registry-k8s
4. Add a possibilty for managers to bypass OPA policies
5. Add roles to pods using spire. Add special role "nsmgr". Accept all register requests in OPA policies if role == "nsmgr" (For example, we can change spiffeID for some pods by adding special labels https://github.com/spiffe/spire/blob/main/support/k8s/k8s-workload-registrar/mode-crd/README.md#label-based-workload-registration)