Function: version_is_older

--Usage--
> version_is_older("version", than: "other version")

Check if a version number is strictly older than another.

Malformed version numbers, including nil, are treated as 0-0-0.

--Parameters--
! Parameter	Type			Description
| @input@	[[type:string]]		Version we want to check.
| @than@	[[type:string]]		Version we want to check against.

--Examples--
> version_is_older("2025-06-28", than: "2026-02-18")  ==  true
> version_is_older("2026-02-18", than: "2026-02-18")  ==  false
> version_is_older(nil, than: "0-0-1")  ==  true