[VFC] Use common mariadb-galera instance

[VFC] Use common mariadb-galera instance

Have following updates for VFC:
- Add section under .Values.global for shared mariadb instance default
info with a condition to instantiate local instance.
- Update the related section of Mariadb-galera under .Values
- Add condition under requirments.yaml to install local mariadb instance
* Note: Since Components initiate their own DBs and Users, there is no
need to initiate the common mariadb-galera with mariadb-init, instead
root password will injected to components to be able to create the DBs.

Have following updates for nslcm, vnflcm, vnfmgr and vnfres:
- Update .Values to accommodate for the new changes in parent .Values
file.
- Update root secret with the condition of having local mariadb or using
the common.
- Update deployments to include the definitions of mariadb service and
port defined in (common/_mariadb.tpl)

Issue-ID: OOM-2840
Signed-off-by: Mahmoud Abdelhamid <mahmoud.abdelhamid@orange.com>
Change-Id: Ia6a8e91ca3978928c4bf336a3a86ab1c6d64597a