GUI: Pull/Push and HTTP/SIP Dialogs Failed graphs are misleading

[FerUy]

While monitoring a stable behaved USSD campaign, graphs of Pull/Push Dialogs Failed and HTTP/SIP Dialogs Failed showed information that might be misleading to a platform administrator. USSD nature of service derives in many MAP errors (mostly due to aborts send by the network caused by user improper handling). A non expert USSD administrator could be false alarmed by looking at these graphs (see attached image, where also it can be seen the bug reported in issue #61). Hence, we should handle the information there in such a way it's distinguishable from a real failure.

A proposal could be having the following counters graphed, titled as Pull/Push Dialog results or similar (avoid failed)
Pull/Push dialogues aborted
Pull/Push dialogues ended (success)
Pull/Push dialogues timeout
Pull/Push dialogues total
(same for current SIP/HTTP Dialog Failed graph)