iwyu

This changes uses its best effort to clean up headers according to iwyu.

Reference:
https://include-what-you-use.org/

Signed-off-by: Nan Zhou <nanzhoumails@gmail.com>
Change-Id: Ibd8bd8735238d6ec101a2428241bb1727e3ac9a9
diff --git a/certificate.hpp b/certificate.hpp
index 46479e4..c96017f 100644
--- a/certificate.hpp
+++ b/certificate.hpp
@@ -2,13 +2,15 @@
 
 #include "watch.hpp"
 
+#include <openssl/ossl_typ.h>
 #include <openssl/x509.h>
 
-#include <filesystem>
 #include <functional>
 #include <memory>
-#include <optional>
-#include <phosphor-logging/elog.hpp>
+#include <sdbusplus/server/object.hpp>
+#include <string>
+#include <string_view>
+#include <unordered_map>
 #include <xyz/openbmc_project/Certs/Certificate/server.hpp>
 #include <xyz/openbmc_project/Certs/Replace/server.hpp>
 #include <xyz/openbmc_project/Object/Delete/server.hpp>