Add CLI that enables NVMe ANA report per volumes and utilizes SPDK ANA-groupIds, ANA states for namespaces and listeners

[leonidc]

Based on ceph-nvmeof issue 122

As per explanation in the issue:
-added optional flag "ana_report" to create-subsystem cli
-added optional flag "enable_ha" to create-subsystem cli
-added optional "ana_grpid" to add-namespace cli
-limited just 4 ANA groups per subsystem
-when added listener and "enable_ha" is configured - set ana_states to all supported ANA groups as "inaccessible"

pushed as 2 commits, they would be squashed

[gbregman]

@leonidc and @caroav , I missed it in the review. But I think it's wrong to use the OMAP state for the ANA stuff in create_listener. The OMAP might not be up to date yet. We should use the local state. Especially when call the SPDK right after it, not the OMAP. So we should not mix the two states. Also, in case we don't find a proper subsystem we don't set "req" but we still use it. This can't happen when using the local state as we should have this subsystem or else the previous call to SPDK to create the listener would have failed but I think it's safer and make the code easier to read to have a guard. So I suggest the following change:

diff --git a/control/grpc.py b/control/grpc.py
index 0f452d6..d1ed4e5 100644
--- a/control/grpc.py
+++ b/control/grpc.py
@@ -533,15 +533,16 @@ class GatewayService(pb2_grpc.GatewayServicer):
                 context.set_details(f"{ex}")
             return pb2.req_status()

-        state = self.gateway_state.omap.get_state()
+        req = None
+        state = self.gateway_state.local.get_state()
         for key,val  in state.items():
-              if (key.startswith(self.gateway_state.omap.SUBSYSTEM_PREFIX + request.nqn)):
+              if (key.startswith(self.gateway_state.local.SUBSYSTEM_PREFIX + request.nqn)):
                      self.logger.debug(f"values of key: {key}  val: {val} \n")
                      req = json_format.Parse(val, pb2.create_subsystem_req())
                      self.logger.info(f" enable_ha :{req.enable_ha} \n")
                      break

-        if req.enable_ha:
+        if req and req.enable_ha:
               for x in range (MAX_ANA_GROUPS):
                    try:
                       ret = rpc_nvmf.nvmf_subsystem_listener_set_ana_state(