This can be used to instantiate the per-SAP tcap_sap_sup and
tcap_tco_server callback module in a simple call like this:
{ok, TcoPid} = tcap_user:start_sap(osmo_sccp_tcap, [7], []).
start of a given TCO is done as follows:
{ok, Pid} = supervisor:start_child(tcap_sup, [[osmo_sccp_tcap, [7],[]]]).
where '7' is the SCCP sub-system number (SSN) to which TCAP should bind.