renamed 15min sample file to test_usage_data
Adds ElectricPowerQualitySummary to test fixture data.
Fixes ReadingQuality steps.
Adds feature steps and view for ElectricPowerQualitySummary
Adds domain model changes and tests for ElectricPowerQualitySummary
Adds unmarshalling of ElectricPowerQualitySummary
[Finishes #56060108]
Fixes ElectricQuality and ElectricUsage summary related links.
Refactors UsagePointBuilder to use latest handler style.