Remove never-supported CSS break-* features

[saschanaz]

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• Link to related issues or pull requests, if any: Remove items that has never been supported #6854, Remove totally unimplemented things #6768

[rachelandrew]

So the always, recto and verso values should stay. Probably worth noting that fragmentation is something I believe is being improved in Blink with LayoutNG so maybe we will see support of these at some point.

Regions is an interesting one, as the Regions spec as is, will probably never be implemented. I think at some point Regions will be brought back, and will definitely rely on fragmentation just like multicol. However given we have no active implementations of the old spec now that Edge is based on Chromium there probably isn't a reason to keep this in our data right now.

So I think we could lose the Regions stuff, but keep the values as mentioned above.

[saschanaz]

@rachelandrew Is always really a thing? It seems CSS Fragmentation Module does not define it. Somehow Gecko supports it saying that CSSWG resolved to add always but I can't confirm whether it is true.

[rachelandrew]

Moved to Fragmentation 4: https://drafts.csswg.org/css-break-4/#valdef-break-before-always

[ddbeck]

Thank you! 🎉