Add a function to request the number of active queries from an ares
channel. This will return the number of inflight requests to dns
servers. Some functions like `ares_getaddrinfo()` when using `AF_UNSPEC`
may enqueue multiple queries which will be reflected in this count.
In the future, if we implement support for queuing (e.g. for throttling
purposes), and/or implement support for tracking user-requested queries
(e.g. for cancelation), we can provide additional functions for
inspecting those queues.
Fix By: Brad House (@bradh352)
It may be useful to wait for the queue to be empty under certain conditions (mainly test cases), expose a function to efficiently do this and rework test cases to use it.
Fix By: Brad House (@bradh352)