sysutils/vagrant: split into vagrant-gitlab that can be used together with gitlab

Added a new port vagrant-gitlab that can be installed with gitlab on the same host.

Currently I do not see another solution as other rubygem version that are installed
by some ports are breaking gitlab and that was the reason to split this.
Some maintainers to do test their changes against all ports which made this step necessary.

You can also install gitlab in a jail to fix these problems.

PR: 287926
(cherry picked from commit 2df3bbf5303028cd33818e1ffa45fa5efba44693)