Hitachi: add an option for hostgroup name format

This blueprint is to add an configuration option which specifies hostgroup(or iSCSI target) name format.

Rules of the format:
* Usable characters are alphanumerics, ".", "@", "_", ":", "-","{" and "}". "{" and "}" can be used only in variables.

* The specified value must start with "HBSD-".
* You can use the following variables:
  - {wwn}: FC driver only. This is replaced with the smallest WWPN of the WWPNs of the connecting node.
  - {ip}: iSCSI driver only. This is replaced with the IP address of the connecting node.
  - {host}: This is replaced with the host name of the connecting node.
* You can use each variable in the specified value no more than once.
* The specified value must include the following variables:
  - FC driver: {wwn}
  - iSCSI driver: {ip}
* The maximum length of a specified value is as follows:
  - FC driver: 64
  - iSCSI driver: 32
* In the length calculation, use the following values as the length of each variable:
  - {wwn}: 16
  - {ip}: 15
  - {host}: 1
* If the specified value includes {host}, the following rules apply:
  - characters that are not permitted for this parameter, they are replaced with "_".
  - If the length of the name after variable replacement exceeds the maximum length of host group (iSCSI target) names, the host name is truncated so that the length of the host groups or iSCSI targets do not exceed the maximum length.

If you specify this parameter, it is recommended that you specify True for the hitachi_group_create parameter to collect necessary information automatically.
* Examples:
  - FC driver: HBSD-{host}-{wwn}
  - iSCSI driver: HBSD-{host}-{ip}