Add logic on newRollUp to pass costMultiplier

[ryankwagner]

To issue:
#768

Add logic to pass costMultiplier into:

• newRollUp (tests WIP)
• createSubset (logic WIP)

Success params:

• Current tests should either not change or any change should be a verified fix.
• At least one example using both, along with their result cost Tuples which are seen in issue Rollup Best Candidate Calc Inconsistent with Equal Cost #766

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