[css-animations][scroll-animations-1] using animation-range in animation shorthand instead of duration and delay

[ydaniv]

Since animation-duration has no meaning for scroll-linked animations, as noted here:

A ScrollTimeline’s duration is 100%.

We could say that <time>-related values have no meaning in animation shorthand values.

Instead, those require an animation-range value, also discussed in #7575.

Currently, animation-range is defined as an alias of animation-delay here: https://drafts.csswg.org/scroll-animations-1/#named-range-animation-declaration.

Perhaps we could define animation to either include <time> values for time-based animations, and have that resolve to animation-delay - which will in turn can be defined as only <time>#; or include only a <timeline-range-name># - and then resolve to animation-range?
Then we could also make these definitions mutually exclusive and also remove the confusion (as discussed in #7901)?
FYI @fantasai @flackr