Update Images Constants

* Updated existing error messages
* Added new error messages

Change-Id: I488772c595d350e7310601d7015cbd00178baa9f
Boot from Block version 2 support

    * Clinet for create V2 boot from block server
    * Models for V2 boot from block and block device V2
    * Unittestst added for models
    * Configuration changes boot from volume V1
    * Fixed review comments
    * Removed Inherited Boot from volume config
    * Added Block Device behaviours
    * Typo fixed
    * Jose review comments fixed
    * Moved metatest to proper location
    * Fixed Jose comments

Change-Id: I4948e70483c12ea0b0c3509b03adb765375b0717
Merge "Update Images Constants"