LibWeb: Add Exposed attribute and IDL spec links where missing

The intent is to use these to autogenerate prototype declarations for
Window and WorkerGlobalScope classes.

And the spec links are just nice to have :^)

Userland/Libraries/LibWeb/SVG/SVGAnimatedLength.idl

@@ -1,5 +1,7 @@
 #import <SVG/SVGLength.idl>
 
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGAnimatedLength
+[Exposed=Window]
 interface SVGAnimatedLength {
     readonly attribute SVGLength baseVal;
     readonly attribute SVGLength animVal;

Userland/Libraries/LibWeb/SVG/SVGElement.idl

@@ -2,6 +2,8 @@
 #import <HTML/HTMLElement.idl>
 #import <HTML/DOMStringMap.idl>
 
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGElement
+[Exposed=Window]
 interface SVGElement : Element {
 };
 

Userland/Libraries/LibWeb/SVG/SVGGeometryElement.idl

@@ -1,6 +1,8 @@
 #import <Geometry/DOMPoint.idl>
 #import <SVG/SVGGraphicsElement.idl>
 
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGGeometryElement
+[Exposed=Window]
 interface SVGGeometryElement : SVGGraphicsElement {
 
     float getTotalLength();

Userland/Libraries/LibWeb/SVG/SVGGraphicsElement.idl

@@ -1,5 +1,7 @@
 #import <SVG/SVGElement.idl>
 
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGGraphicsElement
+[Exposed=Window]
 interface SVGGraphicsElement : SVGElement {
 
 };

Userland/Libraries/LibWeb/SVG/SVGLength.idl

@@ -1,3 +1,5 @@
+// https://svgwg.org/svg2-draft/types.html#InterfaceSVGLength
+[Exposed=Window]
 interface SVGLength {
     const unsigned short SVG_LENGTHTYPE_UNKNOWN = 0;
     const unsigned short SVG_LENGTHTYPE_NUMBER = 1;

Userland/Libraries/LibWeb/SVG/SVGPathElement.idl

@@ -1,5 +1,7 @@
 #import <SVG/SVGGeometryElement.idl>
 
+// https://svgwg.org/svg2-draft/paths.html#InterfaceSVGPathElement
+[Exposed=Window]
 interface SVGPathElement : SVGGeometryElement {
 
 };

Userland/Libraries/LibWeb/SVG/SVGSVGElement.idl

@@ -1,5 +1,7 @@
 #import <SVG/SVGGraphicsElement.idl>
 
+// https://svgwg.org/svg2-draft/struct.html#InterfaceSVGSVGElement
+[Exposed=Window]
 interface SVGSVGElement : SVGGraphicsElement {
 
 };