feat(rum-oversight): improve get totals by replacing a reduce with a copy

[karlpauls]

Improve the performance of get totals in cruncher.

Description

The get totals can be delayed a bit in certain cases and it right now does a reduce over all bundles twice (one time to calculate the parent). It seem possible to replace that with copying the result of the first result and use the copy as the parent.

Motivation and Context

Speed improvements

How Has This Been Tested?

Looking at the ui rendering speed in the console at https://totals--helix-website--karlpauls.hlx.page/tools/oversight/explorer.html?domain=aem.live&domainkey=