Hi,
I am also looking for the “City sample crowds” module
I started a thread here:
https://forums.unrealengine.com/t/accessing-bp-crowd-character-to-use-in-massai-crowd/2097177,
but no replies yet 
I tried migrating the “BP_CrowdCharacter” and even the CitySampleCrowd folder from the big City sample scene to a fresh project. I got some nasty missing C++ class errors though.
I’ll keep investigating in case I find a migration method that works! 
Fingers crossed for a FAB solution soon! 