bolt-gen: use 'enum' instead of 'e:' prefix for enums

use 'enum ' in wirespec instead of 'e:' as an indicator
that a field is an enum.

common/status_wire.csv

@@ -2,17 +2,17 @@
 #include <common/status_wire.h>
 
 msgtype,status_log,0xFFF0
-msgdata,status_log,level,e:log_level,
+msgdata,status_log,level,enum log_level,
 msgdata,status_log,entry,wirestring,
 
 msgtype,status_io,0xFFF1
-msgdata,status_io,iodir,e:log_level,
+msgdata,status_io,iodir,enum log_level,
 msgdata,status_io,who,wirestring,
 msgdata,status_io,len,u16,
 msgdata,status_io,data,u8,len
 
 msgtype,status_fail,0xFFF2
-msgdata,status_fail,failreason,e:status_failreason,
+msgdata,status_fail,failreason,enum status_failreason,
 msgdata,status_fail,desc,wirestring,
 
 msgtype,status_peer_connection_lost,0xFFF3