Add a class to handle RDE commands

This class is used to process RDE packets received from BIOS-BMC
circular buffer. RdeCommandHandler will manage dictionary data,
decode RDE BEJ encoded payloads and push them to the ExternalStorer.

Tested:
Tested this with unit tests.

Signed-off-by: Kasun Athukorala <kasunath@google.com>
Change-Id: Ic66e4e4e2afa523906835713d36015457f324fcc
diff --git a/subprojects/libbej.wrap b/subprojects/libbej.wrap
new file mode 100644
index 0000000..4c03659
--- /dev/null
+++ b/subprojects/libbej.wrap
@@ -0,0 +1,6 @@
+[wrap-git]
+url = https://github.com/openbmc/libbej
+revision = HEAD
+
+[provide]
+libbej = libbej