Retry mechanism for missing metadata

[tdroxler]

When we want to update the metadata, we check which contracts hasn't yet an std-interface-id
For that we call the guessStdInterfaceId function from the node, if we cannot fetch the std-interface id, we set it to None, which is not the same as NULL and don't update the metadata, as we don't know which kind of contract it is.

In mainnet we had a case where we couldn't fetch the interface id (don't know yet why, maybe a version mismatch), but we then never retry to get it, so we were missing some metadata.

We need to have a retry mechanism for the interface id as well as the metadata.