[REF] Interim code cleanup - make the usage of addPayments clearer

[eileenmcnaughton]

Overview

Minor code cleanup - separates some narrow handling for Partially Paid from a main loop

Before

Not clear what addPayments does

After

The status check is called before addPayments - it is clearly specific to 'Partially paid'

Technical Details

The intention is to switch this to creating pending & adding payments per our preferred flow. This is just a step on that path - tests have been added here #16437

Comments

[civibot]

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[yashodha]

@eileenmcnaughton Doc comment for parameter $contributions on line no 4830 does not match actual variable name $contribution

[seamuslee001]

This looks straightforward to me, confirmed doing a grep this affects all the places it is called in the code and makes sense to me and tests have passed merging