trove.coll WITH pending redistribution collateral folded in: the getter adds
getPendingCollateral before returning (TroveManager.sol:797, :799). The separate
pendingCollateral element is the part of this already included, not an addition to it (MK-109).
principal + interestOwed, the quantity every ratio gate compares.
Stored interest, plus live accrual to this block (:788-793), plus pending interest (:801).
trove.principal with pending redistribution principal folded in (TroveManager.sol:798,
:800). That sum is what getNominalICR sorts on (:566-577).
A Trove's live amounts, with each component named rather than indexed.