Adding of possibility of sending of empty TC-CONTINUE not only at the state of TCAP dialog initiating

[vetss]

We need to add a possibility of sending of empty TC-CONTINUE not only at the state of TCAP dialog initiating. We have code now (CamelGatewaySbb.onResponseEvent()):

if (capDialog.getState() == CAPDialogState.InitialReceived ||
prearrangedEnd != null || xmlCAPDialog.getErrorComponents().size() > 0 || 
xmlCAPDialog.getCAPMessages().size() > 0)
{ <sendig response ...> }

We need to to remove of checking of if CAP messages error messages count is 0. Zendesk ticket for it was 33733

[vetss]

Let's think also how to differentiate empty HTTP response / HTTP response with empty TC-CONTINUE

[vetss]

We will force of sending empty TC-CONTINUE (in a dialog is already initiated and no messages / errors to send) by adding a new attribute sendEmptyContinue="true".

The example of HTTP payload (empy TC-CONTINUE):

<?xml version="1.0" encoding="UTF-8" ?>
<dialog capMessagesSize="0" sendEmptyContinue="true">
</dialog>

[vetss]

Fixing by:

https://github.com/RestComm/camelgateway/commit/8116812897ec52bf478f185b1b7c398cb333da08