LibWeb: Fix drawing axis-aligned lines

Previously, these were clipped by the RecordingPainter, which used the
path's bounding box (which in this case is zero width or height). The
fix is to expand the bounding box by the stroke width.

Fixes #22661

Note: This is unrelated to any recent LibGfx changes :^)

Tests/LibWeb/Ref/reference/svg-axis-aligned-lines-ref.html

@@ -0,0 +1,9 @@
+<style>
+* {
+    margin: 0;
+}
+body {
+    background-color: white;
+}
+</style>
+<img src="./images/svg-axis-aligned-lines-ref.png">