zsh completion accepts only direct dependecies for update and remove
zsh completion accepts only direct dependecies for update and remove

Previously direct and indirect dependencies were accepted. If an
indirect dependency was given Paket errored out.

fsprojects/Paket,sergey-tihon/Paket,0x53A/Paket,inosik/Paket,theimowski/Paket,thinkbeforecoding/Paket,0x53A/Paket,thinkbeforecoding/Paket,thinkbeforecoding/Paket,cloudRoutine/Paket,cloudRoutine/Paket,sergey-tihon/Paket,0x53A/Paket,inosik/Paket,cloudRoutine/Paket,fsprojects/Paket,jam40jeff/Paket,cloudRoutine/Paket,jam40jeff/Paket,thinkbeforecoding/Paket,baronfel/Paket,baronfel/Paket,0x53A/Paket,theimowski/Paket