Revert "Add a route target to logical router and add it to all connected networks instead of adding full mesh connection among connected routing instances"

This reverts commit bbefad99d1b91745332445f60adcccab2d7afc42.
Revert "Don't return 404 when a reference is not found, instead fill [ERROR] in place of fq_name to indicate error. Also, remove VN-LR link on dbe_resync since this link is no longer in the schema"

This reverts commit 7be8b8daff25263d5c33ed077eb37257860a734b.