Everywhere: Replace a bundle of dbg with dbgln.

These changes are arbitrarily divided into multiple commits to make it
easier to find potentially introduced bugs with git bisect.

AK/IPv4Address.h

@@ -148,6 +148,14 @@ inline const LogStream& operator<<(const LogStream& stream, const IPv4Address& v
     return stream << value.to_string();
 }
 
+template<>
+struct Formatter<IPv4Address> : Formatter<String> {
+    void format(FormatBuilder& builder, IPv4Address value)
+    {
+        return Formatter<String>::format(builder, value.to_string());
+    }
+};
+
 }
 
 using AK::IPv4Address;