rename headers to match style

Moving headers from ".h" to ".hpp"

Reworked the header inclusion a bit so that host-ipmid is treated as a
library, and local headers aren't.

renamed apphandler.h => apphandler.hpp
renamed chassishandler.h => chassishandler.hpp
renamed globalhandler.h => globalhandler.hpp
renamed sensorhandler.h => sensorhandler.hpp
renamed storageaddsel.h => storageaddsel.hpp
renamed storagehandler.h => storagehandler.hpp
renamed systemintfcmds.h => systemintfcmds.hpp

Change-Id: I9d4ce3dd57e2e996800f9020a10cc10cdf2c3914
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/apphandler.cpp b/apphandler.cpp
index 4a2f2da..c77f014 100644
--- a/apphandler.cpp
+++ b/apphandler.cpp
@@ -1,15 +1,15 @@
-#include "apphandler.h"
+#include "apphandler.hpp"
 
 #include "app/channel.hpp"
 #include "app/watchdog.hpp"
 #include "ipmid.hpp"
-#include "nlohmann/json.hpp"
 #include "sys_info_param.hpp"
 #include "transporthandler.hpp"
 #include "types.hpp"
 #include "utils.hpp"
 
 #include <arpa/inet.h>
+#include <host-ipmid/ipmid-api.h>
 #include <limits.h>
 #include <mapper.h>
 #include <stdint.h>
@@ -17,7 +17,7 @@
 #include <systemd/sd-bus.h>
 #include <unistd.h>
 
-#include "host-ipmid/ipmid-api.h"
+#include <nlohmann/json.hpp>
 
 #if __has_include(<filesystem>)
 #include <filesystem>