lib: Add new if_link_params structure

This new structure is the basis to get new link parameters for
Traffic Engineering from Zebra/interface layer to OSPFD and ISISD
for the support of Traffic Engineering

* lib/if.[c,h]: link parameters struture and get/set functions
* lib/command.[c,h]: creation of a new link-node
* lib/zclient.[c,h]: modification to the ZBUS message to convey the
  link parameters structure
* lib/zebra.h: New ZBUS message
* lib/memtypes.c: Add new memory type for Traffic Engineering support

Signed-off-by: Olivier Dugeon <olivier.dugeon@orange.com>
diff --git a/lib/zebra.h b/lib/zebra.h
index 7c4adf1..cb83a11 100644
--- a/lib/zebra.h
+++ b/lib/zebra.h
@@ -425,7 +425,8 @@
 #define ZEBRA_HELLO                       23
 #define ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB    24
 #define ZEBRA_VRF_UNREGISTER              25
-#define ZEBRA_MESSAGE_MAX                 26
+#define ZEBRA_INTERFACE_LINK_PARAMS       26
+#define ZEBRA_MESSAGE_MAX                 27
 
 /* Marker value used in new Zserv, in the byte location corresponding
  * the command value in the old zserv header. To allow old and new