Ability to control the source of power monitoring metrics

Power Monitoring can get metrics either directly from things such as RAPL or it can use modelling to estimate power usage (such as in virtual machine environments).

We should be able to give customers the ability to choose which metric source they are wanting to use.

For example, some customers may not want to use model estimates if its not fully support and only use directly gathered metrics.

This could be accomplished with a flag/config that a customer could configure. Care may need to be taken to ensure that we don't break existing environments (such as only changing the default behaviour on new deployments instead of existing ones)