gdb: Add pretty printer for managed_bytes
gdb: Add pretty printer for managed_bytes

avikivity/scylla,avikivity/scylla,avikivity/scylla,duarten/scylla,duarten/scylla,scylladb/scylla,duarten/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla