tools/qubesd-query: handle events-based methods
tools/qubesd-query: handle events-based methods

Pass the data as it arrives, instead of buffering it all.

QubesOS/qubes-issues#2622

woju/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,woju/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin,woju/qubes-core-admin,marmarek/qubes-core-admin