Add a loading indicator if a request or payment exists on-chain but hasn't been indexed by the storage or payments subgraph yet

[MantisClone]

Problem

When Payment Widget pays and persists an in-memory request, the resulting Request Scan link shows a "404 Page Not Found" error screen. This is because the storage subgraph has not yet indexed the new request creation due to the Pay before persist flow.

Proposed Solution

Figure out a way to detect if a request or a payment exists but hasn't been indexed yet. If so, display a loading indicator with a retry flow instead of "404 Page Not Found".

• Figure out how the "Not Found" page should look for all searches.

[MantisClone]

I don't know how to do this. But Etherscan seems to do it.