[sb2] Add mapping for aligned workspace mount points. JB#49476
Applies when sb2 is used under the SDK build engine.
Workspace directories used to be mounted at fixed paths under /home. Now the mount point paths are chosen in a way that they align with the source paths on host (e.g. "/home/user/work" -> "/home/user/work", "C:\Users\user\work" -> "/c/Users/user/work").