nvmeof: add VolumeExpansion_ONLINE Capability

Add EXPAND_VOLUME capability to NodeServer for online volume expansion support

Signed-off-by: gadi-didi <gadi.didi@ibm.com>

Author: gadididi

internal/nvmeof/identity/identityserver.go

@@ -51,6 +51,13 @@ func (is *Server) GetPluginCapabilities(
 					},
 				},
 			},
+			{
+				Type: &csi.PluginCapability_VolumeExpansion_{
+					VolumeExpansion: &csi.PluginCapability_VolumeExpansion{
+						Type: csi.PluginCapability_VolumeExpansion_ONLINE,
+					},
+				},
+			},
 		},
 	}, nil
 }