Enhancements to KPI Computation MS for Kohn Release

- Changes to support two types of PM XML schema
- Throw an exception for Ratio and SumRatio computation when
  minimum operand size is not satisfied

Issue-ID: DCAEGEN2-3193
Signed-off-by: Malarvizhi Paramasivam <malarvizhi.44@wipro.com>
Change-Id: Ie9672bb11a5e98aa681bd1c7c7db59ea2be46112
10 files changed