idl: fix generated writers when member functions are used
idl: fix generated writers when member functions are used

When using member name in an idetifer of generated class or method
idl compiler should strip the trailing '()'.

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