Refactors alarm creation to comply with changes regarding the use of tags instead of fixed fields

MON changed alarms to include the concept of tags. POL process for alarm creation has
modified to comply with this.
Also, some refactoring has been done in the autoscaling service.

Change-Id: Iaf18262d05727bbb8ff06e83bce13e991aecab6c
Signed-off-by: Benjamin Diaz <bdiaz@whitestack.com>