Map img/object width/height attributes to dimension properties

[nicoburns]

Summary

img and object were missing from the embedded-content dimension attribute mapping in stylo.rs, so e.g. width="100%" on an <img> was ignored (only plain numeric attribute values were picked up as intrinsic-size overrides by the replaced measure function). Adding them makes percentage/length dimension attributes resolve as CSS width/height, fixing e.g. css/CSS2/inline-svg-100-percent-in-body.html (~10 WPT tests when combined with #634's intrinsic sizing).

Split out of #634.

Link to Devin session: https://dioxus.staging.devinenterprise.com/sessions/51256d0b440341bd874c6dc59e138478
Requested by: @nicoburns

WPT results

49 newly passing, 5 newly failing (net +44).

Full diff (54 changed tests)

+ Fail => Pass css/CSS2/backgrounds/background-001.xht
+ Fail => Pass css/CSS2/backgrounds/background-002.xht
+ Fail => Pass css/CSS2/backgrounds/background-003.xht
+ Fail => Pass css/CSS2/backgrounds/background-006.xht
+ Fail => Pass css/CSS2/backgrounds/background-007.xht
+ Fail => Pass css/CSS2/backgrounds/background-008.xht
+ Fail => Pass css/CSS2/backgrounds/background-009.xht
+ Fail => Pass css/CSS2/backgrounds/background-010.xht
+ Fail => Pass css/CSS2/backgrounds/background-014.xht
+ Fail => Pass css/CSS2/backgrounds/background-018.xht
+ Fail => Pass css/CSS2/backgrounds/background-022.xht
+ Fail => Pass css/CSS2/backgrounds/background-087.xht
+ Fail => Pass css/CSS2/backgrounds/background-182.xht
+ Fail => Pass css/CSS2/backgrounds/background-328.xht
+ Fail => Pass css/CSS2/backgrounds/background-329.xht
- Pass => Fail css/CSS2/backgrounds/background-attachment-applies-to-007.xht
- Pass => Fail css/CSS2/backgrounds/background-attachment-applies-to-009.xht
- Pass => Fail css/CSS2/backgrounds/background-attachment-applies-to-012.xht
- Pass => Fail css/CSS2/backgrounds/background-attachment-applies-to-013.xht
- Pass => Fail css/CSS2/backgrounds/background-attachment-applies-to-014.xht
+ Fail => Pass css/CSS2/backgrounds/background-image-cover-002.xht
+ Fail => Pass css/CSS2/backgrounds/background-image-cover-004.xht
+ Fail => Pass css/CSS2/backgrounds/background-image-cover-attachment-001.xht
+ Fail => Pass css/CSS2/backgrounds/background-image-transparency-001.xht
+ Fail => Pass css/CSS2/backgrounds/background-repeat-001.xht
+ Fail => Pass css/CSS2/backgrounds/background-repeat-002.xht
+ Fail => Pass css/CSS2/backgrounds/background-repeat-003.xht
+ Fail => Pass css/CSS2/backgrounds/background-repeat-005.xht
+ Fail => Pass css/CSS2/borders/border-bottom-width-003.xht
+ Fail => Pass css/CSS2/borders/border-bottom-width-025.xht
+ Fail => Pass css/CSS2/borders/border-bottom-width-058.xht
+ Fail => Pass css/CSS2/borders/border-bottom-width-069.xht
+ Fail => Pass css/CSS2/borders/border-bottom-width-080.xht
+ Fail => Pass css/CSS2/borders/border-top-width-003.xht
+ Fail => Pass css/CSS2/borders/border-top-width-025.xht
+ Fail => Pass css/CSS2/borders/border-top-width-058.xht
+ Fail => Pass css/CSS2/borders/border-top-width-069.xht
+ Fail => Pass css/CSS2/borders/border-top-width-080.xht
+ Fail => Pass css/CSS2/borders/border-width-shorthand-001.xht
+ Fail => Pass css/CSS2/borders/border-width-shorthand-002.xht
+ Fail => Pass css/CSS2/borders/border-width-shorthand-003.xht
+ Fail => Pass css/CSS2/borders/border-width-shorthand-004.xht
+ Fail => Pass css/CSS2/floats-clear/float-replaced-width-011.xht
+ Fail => Pass css/CSS2/inline-svg-100-percent-in-body.html
+ Fail => Pass css/CSS2/normal-flow/block-replaced-width-006.xht
+ Fail => Pass css/CSS2/normal-flow/inline-block-replaced-width-006.xht
+ Fail => Pass css/CSS2/normal-flow/inline-replaced-width-006.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-006.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-013.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-020.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-027.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-034.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-069.xht
+ Fail => Pass css/CSS2/positioning/absolute-replaced-width-076.xht

_{Generated by the WPT workflow.}

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