Adapt checks to the new rename replication feature

With the introduction of the rename replication feature, the check for
project existence has to be brought out of the RenamePreconditions and
put in RenameCommand. This is done to avoid NullPointerException on a
non-existent project when the "--replication" option is used.

Change-Id: Ibc6e9123b9f86ef29d9106031841cd3f22fa06a5