Added extra buffer to Delta Performace Tests

Added extra buffer to Delta Performace Tests

The existing buffer time on delta report related performance tests was
not sufficient.

Added 4-5 seconds of extra buffer time across all tests.

Removed the method resetTestAnchorData as it was causing Query API
related tests to fail.

Implemented an alternative approach to test Apply Delta Report
performance test, where the delta report is applied to a separate anchor
named openroadm-modified1 instead of openroadm1.

Issue-ID: CPS-2996
Change-Id: Ib063e0470b487105e31dc3fc1211f630a1392d8a
Signed-off-by: Arpit Singh <AS00745003@techmahindra.com>