explicit use of std::vector instead of buffer/Buffer

There were several scoped 'using buffer = std::vector<uint8_t>;' in
header files. This consolidates the code base to use
std::vector<uint8_t> instead of buffer or Buffer. This makes the code
easier to read and debug.

Change-Id: I918a0f6ca9b8e4b9d331175dccff45cbf4c8379d
Signed-off-by: Vernon Mauery <vernon.mauery@linux.intel.com>
diff --git a/message_handler.hpp b/message_handler.hpp
index 11cc42a..7fb06f1 100644
--- a/message_handler.hpp
+++ b/message_handler.hpp
@@ -68,7 +68,7 @@
          *
          *  @param[in] input - SOL Payload
          */
-        void sendSOLPayload(const sol::Buffer& input);
+        void sendSOLPayload(const std::vector<uint8_t>& input);
 
         /** @brief Send the unsolicited IPMI payload to the remote console.
          *