mgr/dashboard: cephadm-e2e script: improvements

mgr/dashboard: cephadm-e2e script: improvements

Improvements and some adaptations related to the jenkins job.

Fixes: https://tracker.ceph.com/issues/51612
Signed-off-by: Alfonso Martínez <almartin@redhat.com>
(cherry picked from commit 65b75000b7694cb3cbe617bbec28c513a2522be8)

    Conflicts:
        doc/dev/developer_guide/dash-devel.rst
        - Put changes in HACKING.rst as this file does not exist in the octopus branch.
        src/pybind/mgr/dashboard/ci/cephadm/bootstrap-cluster.sh
        - Resolve conflict originated by code that is deleted anyway.

Signed-off-by: Alfonso Martínez <almartin@redhat.com>