Isolate Delta Report performance test data

Isolate Delta Report performance test data

- Performance tests for Delta report required creation of an anchor used
  only for performance tests of Delta Report
- Current approach made this anchor available to other performance tests
  causing them to fail.
- Updated approach isolates the test data for Delta Report to
  DeltaPerfTest class.
- removed addModifiedOpenRoadData() method as it is no longer needed to
  create anchor for Delta Report tests.

Issue-ID: CPS-3012
Change-Id: Ib7e22ce937fbbafa77c42a09d1c2eaed3c00796d
Signed-off-by: Arpit Singh <AS00745003@techmahindra.com>