/node/quotes/self fails when some of the collateral becomes expired

[achamayou]

/node/quotes/self validates the quote to extract claims such as mrenclave. When some of the collateral expires (eg. the CRL), even though it had been valid at join time, users are unable to extract claims and the endpoint returns an error.

The right fix would be to validate the collateral against the timestamps of the quote in this context, rather than the current time, but oe_verify_evidence() doesn't provide that functionality. For now we can parse those claims at join time, store them in the ledger and retrieve them from there.