Clear the associations both at runtime and during restore if corresponding PEL is deleted

[devenrao]

When a pel is deleted corresponding guard records are not deleted, The guard records will be pointing to an errolog id and associations which does not exist.

At runtime=
Need to subscribe for error log object delete and when the object is deleted update the hw-isolation entry to remove the assocations.

Restore
Check for the error log object based on the path we get from assosiations and check if it stil exist, if it doesn;t then clear the associations.

Jun 23 12:11:41 everjmt03bmc bmcweb[2576]: (2022-06-23 12:11:41) [ERROR "error_log_utils.hpp":42] DBus response error [53 : Invalid request descriptor] when tried to get the Hidden property from the given error log object /xyz/openbmc_project/logging/entry/337