Maximum zero time return alternative for ICooldown.getRemaining()

[CosimoTiger]

Request description

Developers will typically use ICooldown.getRemaining() to display to a player how much more they have to wait; displaying negative values usually doesn't make sense, though it can be useful, but therefore we should offer negative remaining time only as a secondary, and Math.max(0, remainder) as a primary feature.

Acceptance criteria

ICooldown.getRemaining() and .getRemaining(TimeUnit) or a new similar method returns 0 at minimum and never negative times when the cooldown has over-expired. Needs to be included in the tests.