Cloud Metering - Add additional token substitutions for metering email templates

For templates "Total cost of all instances of user reached or crossed budget" , and "Total cost of all instances of group reached or crossed budget", it does not have anything to do with individual instances. The current email templates for these two emails have tokens for individual instance and instance_ids. Instead, it the email should have more useful information such as Total Cost, and Total Budgets that were surpassed.