Feature Description:

AIT: time of an asynchronous invocation in the current microservice execution
Scope: Invocation
Detail description:
    AIT is time of an asynchronous invocation in the current microservice execution. For example, the invocation chain of the
current microservice execution is:
       A -> B -> C -> D
	           -> E
	In this chain, the invocations of A, B and C are synchronous, and invocations of C, D and E are asynchronous. The AIT is the
total time of the asynchronous invocations of "C -> D" and "C -> E"