What
---
1. Add KAS to be cell local
2. Created a more detailed architecture diagram for KAS

Why
---
1. Things end up simpler since we don't have a global service
2. Adding this amount of detail to the main architecture diagram will
   end up being noisy, having a separate diagram will help split the
   information.

Reference: &11710


Signed-off-by: Steve Xuereb <sxuereb@gitlab.com>