https://wpt.fyi/results/css/css-contain/container-queries/container-units-svglength.html?label=master&label=experimental&product=chrome&product=firefox&product=safari&aligned&view=interop&q=label%3Ainterop-2023-container
<rdar://problem/106739462>
Currently our SVGLength code only supports unit types defined in SVGLengthType enum: enum class SVGLengthType : uint8_t { Unknown = 0, Number, Percentage, Ems, Exs, Pixels, Centimeters, Millimeters, Inches, Points, Picas }; Per spec (https://svgwg.org/svg2-draft/types.html#InterfaceSVGLength) other types can be supported too. This is not a container unit specific issue but a general SVG issue.