Support configuration of TCONTs as per WT-385 and auto-allocation of alloc-ids

• As an operator, I should be able to provision a TCONT for the ONU with an existing traffic descriptor profile
• As an operator, I should be able to retrieve the provisioned TCONT
• As an operator, I should be able to change the traffic descriptor profile for a TCONT

Additional Notes:

• alloc-ids should be allocated for the TCONT
• generic IAdapter interface to be provided that will be used by OLT and ONU adapters for TCONT/alloc-id/BW configuration
• In the best interest of schedules/timing, in the first step(e.g. POC-3 & trial), assume the queueing model to be supported (to be detailed) (i.e. no configuration of queueing model)
• The concerned ONU should receive upstream grants upon provisioning of TCONT for the ONU