LibWeb/SVG: Implement the SVGAElement.referrerPolicy attribute

Author: https://github.com/tcl3
Commit: 31e8189f9f
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5412
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/shannonbooth

Tests/LibWeb/Text/expected/HTML/referrerPolicy-attribute.txt

@@ -40,3 +40,10 @@ script referrerPolicy value after setting to null: ''
 script referrerPolicy value after setting to "NO-REFERRER": 'no-referrer'
 script referrerPolicy value after setting to "": ''
 script referrerPolicy value after calling removeAttribute: ''
+svg:a referrerPolicy initial value: ''
+svg:a referrerPolicy value after setting to "invalid": ''
+svg:a referrerPolicy value after setting to "no-referrer": 'no-referrer'
+svg:a referrerPolicy value after setting to null: ''
+svg:a referrerPolicy value after setting to "NO-REFERRER": 'no-referrer'
+svg:a referrerPolicy value after setting to "": ''
+svg:a referrerPolicy value after calling removeAttribute: ''

Tests/LibWeb/Text/expected/wpt-import/svg/idlharness.window.txt

@@ -2,8 +2,8 @@ Harness status: OK
 
 Found 1781 tests
 
-940 Pass
-841 Fail
+942 Pass
+839 Fail
 Pass	idl_test setup
 Pass	idl_test validation
 Pass	Partial interface Document: original interface defined
@@ -1560,7 +1560,7 @@ Pass	SVGAElement interface: attribute relList
 Pass	SVGAElement interface: attribute hreflang
 Pass	SVGAElement interface: attribute type
 Fail	SVGAElement interface: attribute text
-Fail	SVGAElement interface: attribute referrerPolicy
+Pass	SVGAElement interface: attribute referrerPolicy
 Fail	SVGAElement interface: attribute origin
 Fail	SVGAElement interface: attribute protocol
 Fail	SVGAElement interface: attribute username
@@ -1582,7 +1582,7 @@ Pass	SVGAElement interface: objects.a must inherit property "relList" with the p
 Pass	SVGAElement interface: objects.a must inherit property "hreflang" with the proper type
 Pass	SVGAElement interface: objects.a must inherit property "type" with the proper type
 Fail	SVGAElement interface: objects.a must inherit property "text" with the proper type
-Fail	SVGAElement interface: objects.a must inherit property "referrerPolicy" with the proper type
+Pass	SVGAElement interface: objects.a must inherit property "referrerPolicy" with the proper type
 Fail	SVGAElement interface: objects.a must inherit property "origin" with the proper type
 Fail	SVGAElement interface: objects.a must inherit property "protocol" with the proper type
 Fail	SVGAElement interface: objects.a must inherit property "username" with the proper type