Produce DOT file for repositories dependency visualization

(cherry picked from commit 2f1b69706365edffac262b4d0233f141c2830de9)
List of repositories required to be built before target repo

(cherry picked from commit b37d20b57aad8e3f796132bf65a311a70111f4bb)
BZ-1141816 Centralizing user and session retrieval so that REST requests are also handled