LibWeb: Properly serialize position/edge style values

Author: https://github.com/Gingeh
Commit: 84150f972f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2651
Reviewed-by: https://github.com/AtkinsSJ ✅
Reviewed-by: https://github.com/awesomekling

Tests/LibWeb/Text/expected/css/CSSStyleDeclaration-all-supported-properties-and-default-values.txt

@@ -159,7 +159,7 @@ All supported properties and their default values exposed from CSSStyleDeclarati
 'aspect-ratio': 'auto'
 'backdropFilter': 'none'
 'backdrop-filter': 'none'
-'background': 'rgba(0, 0, 0, 0) none left 0% top 0% auto auto repeat scroll padding-box border-box'
+'background': 'rgba(0, 0, 0, 0) none 0% 0% auto auto repeat scroll padding-box border-box'
 'backgroundAttachment': 'scroll'
 'background-attachment': 'scroll'
 'backgroundClip': 'border-box'
@@ -170,12 +170,12 @@ All supported properties and their default values exposed from CSSStyleDeclarati
 'background-image': 'none'
 'backgroundOrigin': 'padding-box'
 'background-origin': 'padding-box'
-'backgroundPosition': 'left 0% top 0%'
-'background-position': 'left 0% top 0%'
-'backgroundPositionX': 'left 0%'
-'background-position-x': 'left 0%'
-'backgroundPositionY': 'top 0%'
-'background-position-y': 'top 0%'
+'backgroundPosition': '0% 0%'
+'background-position': '0% 0%'
+'backgroundPositionX': '0%'
+'background-position-x': '0%'
+'backgroundPositionY': '0%'
+'background-position-y': '0%'
 'backgroundRepeat': 'repeat'
 'background-repeat': 'repeat'
 'backgroundSize': 'auto auto'
@@ -430,8 +430,8 @@ All supported properties and their default values exposed from CSSStyleDeclarati
 'min-width': 'auto'
 'objectFit': 'fill'
 'object-fit': 'fill'
-'objectPosition': 'left 50% top 50%'
-'object-position': 'left 50% top 50%'
+'objectPosition': '50% 50%'
+'object-position': '50% 50%'
 'opacity': '1'
 'order': '0'
 'outline': 'rgb(0, 0, 0) none medium'