[CSS syntax patches] Fix sameAs, handle legacyAliasOf links

[tidoust]

The sameAs logic was almost correct but failed to report the syntax in the end.

While reviewing differences with mdn/data to update CSSTree, it also occurred to me that we never set the syntax of properties defined as "legacy name aliases", even though we could with the same (very slighty extended) patching logic. Done here too (it could be argued that this could be done by Reffy as post-processing, done here for the time being to reuse the logic).

This would set the syntax of legacy properties:

• -webkit-align-items to that of align-items
• -webkit-align-content to that of align-content
• -webkit-align-self to that of align-self
• -webkit-animation-name to that of animation-name
• -webkit-animation-duration to that of animation-duration
• -webkit-animation-timing-function to that of animation-timing-function
• -webkit-animation-iteration-count to that of animation-iteration-count
• -webkit-animation-direction to that of animation-direction
• -webkit-animation-play-state to that of animation-play-state
• -webkit-animation-delay to that of animation-delay
• -webkit-animation-fill-mode to that of animation-fill-mode
• -webkit-animation to that of animation
• -webkit-backface-visibility to that of backface-visibility
• -webkit-background-clip to that of background-clip
• -webkit-background-origin to that of background-origin
• -webkit-background-size to that of background-size
• -webkit-border-bottom-left-radius to that of border-bottom-left-radius
• -webkit-border-bottom-right-radius to that of border-bottom-right-radius
• -webkit-border-top-left-radius to that of border-top-left-radius
• -webkit-border-top-right-radius to that of border-top-right-radius
• -webkit-border-radius to that of border-radius
• -webkit-box-shadow to that of box-shadow
• -webkit-box-sizing to that of box-sizing
• -webkit-flex to that of flex
• -webkit-flex-basis to that of flex-basis
• -webkit-flex-direction to that of flex-direction
• -webkit-flex-flow to that of flex-flow
• -webkit-flex-grow to that of flex-grow
• -webkit-flex-shrink to that of flex-shrink
• -webkit-flex-wrap to that of flex-wrap
• -webkit-filter to that of filter
• -webkit-justify-content to that of justify-content
• -webkit-mask to that of mask
• -webkit-mask-box-image to that of mask-border
• -webkit-mask-box-image-outset to that of mask-border-outset
• -webkit-mask-box-image-repeat to that of mask-border-repeat
• -webkit-mask-box-image-slice to that of mask-border-slice
• -webkit-mask-box-image-source to that of mask-border-source
• -webkit-mask-box-image-width to that of mask-border-width
• -webkit-mask-clip to that of mask-clip
• -webkit-mask-composite to that of mask-composite
• -webkit-mask-image to that of mask-image
• -webkit-mask-origin to that of mask-origin
• -webkit-mask-position to that of mask-position
• -webkit-mask-repeat to that of mask-repeat
• -webkit-mask-size to that of mask-size
• -webkit-order to that of order
• -webkit-perspective to that of perspective
• -webkit-perspective-origin to that of perspective-origin
• -webkit-transform-origin to that of transform-origin
• -webkit-transform-style to that of transform-style
• -webkit-transform to that of transform
• -webkit-transition-delay to that of transition-delay
• -webkit-transition-duration to that of transition-duration
• -webkit-transition-property to that of transition-property
• -webkit-transition-timing-function to that of transition-timing-function
• -webkit-transition to that of transition
• -webkit-text-size-adjust to that of text-size-adjust
• grid-row-gap to that of row-gap
• grid-column-gap to that of column-gap
• grid-gap to that of gap
• font-stretch to that of font-width