Add CSS and SVG animations, fill missing Web Animations

[jamesnw]

This is mostly backfilling older functionality. It adds a new Animation Group as well.

Low/false baseline items did not seem particularly feature-worthy.

[ddbeck]

I had a look around and I think SMIL is a bit more common, though it's possible I'm looking in the wrong places. Looking at Stack Overflow questions for example, I see lots of SMIL mentions or <animate> as metonymy. Because there are other elements, I don't want to go down the <animate> route, so unless I'm missing something I think SMIL might be the way to go (or something verbose like "SMIL SVG animations").

For what it's worth here, my main goal here is to let the name be distinctive (e.g., if you're skimming a list of features, I don't want us to end up with a bunch of "SVG …" features that lose distinctiveness).

[captainbrosset]

For what it's worth:

[captainbrosset]

"SVG animation" (singular) shows a bit more searches than the plural form, but still way below smil.

[jamesnw]

I decided to go with SMIL SVG animations. In looking at Stackoverflow, there were a lot of people talking about animating in SVG with <animate* but not talking about it as SMIL, so I think it is more understandable with both SMIL and SVG.

[ddbeck]

I sent the (non-blocking) mdn/browser-compat-data#24607 to remove the ranges. It shouldn't change the overall date, just remove the uncertainty.