Introduce ComputerSystem schema

Initial commit which adds:
- ComputerSchemaCollection GET method
- ComputerSchema GET, PATCH methods

Tested on x86 and aspeed
- RSV pass for ComputerSchema
- bmcweb interface no regression
- smbios interface tested with demo app

Change-Id: Ib64084c5888bc511a24f954a6bc062ca920addbe
Signed-off-by: Lewanczyk, Dawid <dawid.lewanczyk@intel.com>
diff --git a/redfish-core/lib/chassis.hpp b/redfish-core/lib/chassis.hpp
index 6047f3e..95f4634 100644
--- a/redfish-core/lib/chassis.hpp
+++ b/redfish-core/lib/chassis.hpp
@@ -27,7 +27,7 @@
 // Note, this is not a very useful variant, but because it isn't used to get
 // values, it should be as simple as possible
 // TODO(ed) invent a nullvariant type
-using VariantType = sdbusplus::message::variant<std::string>;
+using VariantType = sdbusplus::message::variant<bool, std::string>;
 using ManagedObjectsType = std::vector<std::pair<
     sdbusplus::message::object_path,
     std::vector<std::pair<std::string,