Full support for the UsageSummary Resource

[jateeter]

Support for the UsageSummary API (Equivalent to ElectricPowerUsageSummary API)

[jateeter]

Added the APIs, but also need to deprecate the ElectricPowerUsageSummary apis. will enter a new issue for that. And testing these UsageSummary apis depends on deployment of the support on services, so I'll leave this open