LibUnicode: Generate the path to emoji images alongside emoji data

This will provide for quicker emoji lookups, rather than having to
discover and allocate these paths at runtime before we find out if they
even exist.

Userland/Libraries/LibUnicode/Emoji.h

@@ -32,6 +32,7 @@ enum class EmojiGroup : u8 {
 
 struct Emoji {
     StringView name;
+    Optional<StringView> image_path;
     EmojiGroup group { EmojiGroup::Unknown };
     u32 display_order { 0 };
     ReadonlySpan<u32> code_points;