Sidecar Hangs After Bad Request

[Imod7]

Description

A user reported that Sidecar hangs for a very long time ( > 15 secs) after a bad request and shared the error msg below as an example:

BadRequestError: The address xxx is not a stash address.

Additionaly, they asked if we can have this request fail quickly and/or a better way to handle this.

Steps to Reproduce
Based on the error message that the user reported, they are probably querying the /accounts/{accountId}/staking-infoendpoint. After testing this endpoint with some random accounts in Polkadot, I don't see any delays in the response. It is almost instant. It is basically the first check we do after retrieving the controller account with this call. So I do not see any bottlenecks in the code but we could run some benchmarks again just to be sure.

Possible other issues

• It could be related to memory issues/leaks so linked to this [Meta] Performance #1361
• We should also take into account that it can also be due to the specific setup of the user, e.g. network settings, VPN, using public endpoints with rate limiting. To be sure that this is not related to their setup, we could run tests with a Sidecar instance locally connected to a local node.

Notes
Also mentioned in this Substrate Stack Exchange question