Multi-host support for GET routes in systems.hpp

Add support for multi-host GET request-handling under the
/redfish/v1/Systems/{computerSystemId}/ redfish resource.

All multi-host supported redfish URIs can be found in this listing [1].

Multi-host meson options needed:
-Dexperimental-redfish-multi-computer-system=enabled

Tested: Validator passes on single-host machine and yv4 qemu emulation.

[1] https://gerrit.openbmc.org/c/openbmc/bmcweb/+/76118

Change-Id: I67c17c3dd7a354fa9a2ebbc56d4def7a7e788909
Signed-off-by: Oliver Brewka <oliver.brewka@9elements.com>
diff --git a/test/meson.build b/test/meson.build
index 09b29d3..f66bc52 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -42,6 +42,7 @@
     'redfish-core/include/utils/query_param_test.cpp',
     'redfish-core/include/utils/sensor_utils_test.cpp',
     'redfish-core/include/utils/stl_utils_test.cpp',
+    'redfish-core/include/utils/systems_utils_test.cpp',
     'redfish-core/include/utils/time_utils_test.cpp',
     'redfish-core/lib/chassis_test.cpp',
     'redfish-core/lib/ethernet_test.cpp',