LibGfx: Add a method to get a specific tag from an ICC Profile

Author: https://github.com/AtkinsSJ
Commit: 1066831b39
Pull-request: https://github.com/SerenityOS/serenity/pull/19691
Reviewed-by: https://github.com/LucasChollet
Reviewed-by: https://github.com/kleinesfilmroellchen ✅
Reviewed-by: https://github.com/nico ✅

Userland/Libraries/LibGfx/ICC/Profile.h

@@ -254,6 +254,11 @@ public:
         return {};
     }
 
+    Optional<TagData const&> tag_data(TagSignature signature) const
+    {
+        return m_tag_table.get(signature).map([](auto it) -> TagData const& { return *it; });
+    }
+
     size_t tag_count() const { return m_tag_table.size(); }
 
     // Only versions 2 and 4 are in use.