Remove Redfish Health Rollup

Health Rollup is unmaintained after the original author, James Feist,
left several years ago. Calls for an owner have gone unanswered. Its
implementation and design was only half done.

bmcweb is removing the redfish-health-populate option and its limited
support at https://gerrit.openbmc.org/c/openbmc/bmcweb/+/70450.

The option has been defaulted off for 10 months with no upstream layers
enabling it, and no discussions have been raised about keeping it.

It was always limited to a few resources.
A future "HealthRollup" can be proposed. Caution here that health rollup
is nontrivial to get correct, performance problems are a concern, and
hesitancy from the bmcweb maintainers due to multiple calls to get
people to own health rollup as a whole went completely unanswered.
Redfish probably needs better guidance on how health rollup needs to
work functionally.

Change-Id: Ib2d57ad05696ae81e41dcba31584b8786ba91714
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>

Author: gtmills