Fix sdlcli healthcheck DBAAS status in SEP install

Fix sdlcli healthcheck DBAAS status in SEP install

Implement reading of the new environment variable 'DBAAS_NODE_COUNT'
what defines how many DBAAS nodes there has been configured to be in
one SDL cluster group. For the time being in HA deployment value is 3
and in standalone deployment 1. With help of this variable sdlcli
'healthcheck' -command is able to show NOK status in case any configured
DBAAS pod is not present.
Refactor also output writing of the sdlcli 'healthcheck' -command to
show health status in a table layout.

Issue-Id: RIC-113

Signed-off-by: Timo Tietavainen <timo.tietavainen@nokia.com>
Change-Id: I1d677c6a78eda67e3bcfdf814654710b00dac270