Add clang-tidy file

This commit implements a clang-tidy file, and makes
some changes to get it to pass.
Most changes are naming or mechanical in nature.

Tested:
CI passed in docker.

Change-Id: I1f9acf546542c839b8f9facb5b8beff37c0d5909
Signed-off-by: Pavithra Barithaya <pavithra.b@ibm.com>
diff --git a/manager.hpp b/manager.hpp
index 02dd253..e8c28e9 100644
--- a/manager.hpp
+++ b/manager.hpp
@@ -116,7 +116,7 @@
                                  sd_bus_error* retError);
 
     /** @brief The string of time mode property */
-    static constexpr auto PROPERTY_TIME_MODE = "TimeSyncMethod";
+    static constexpr auto propertyTimeMode = "TimeSyncMethod";
 };
 
 } // namespace time