gbmcweb: Add Redfish BootOptions GET (collection and member)

Adds read-only Redfish support for UEFI boot options backed by
SystemRegistry:
- ComputerSystem Boot.BootOptions link (when a SystemRegistry is present).
- GET /redfish/v1/Systems/<id>/Boot/BootOptions/ returns the collection.
- GET /redfish/v1/Systems/<id>/Boot/BootOptions/<ref>/ returns a member;
  404 if the boot option does not exist.
Google-Bug-Id:539554519
PiperOrigin-RevId: 994725773
Change-Id: I18efa80e73b52e90b358824f5b1c38e2571f5b6f

gbmcweb

diff --git a/gbmcweb b/gbmcweb
index 13c2698..fed3da8 160000
--- a/gbmcweb
+++ b/gbmcweb
@@ -1 +1 @@
-Subproject commit 13c26984d070d2d3b23ab38f996357a679ff9a5e
+Subproject commit fed3da8b136a3beb9cd10d8f08780885335847e7