Change errors to use thiserror

[hackaugusto]

• Change the error implementation to use thiserror crate

related: 0xPolygonMiden/miden-node#62

[bobbinth]

The main reason for why we are not using this currently is that thiserror requires std. Would would be the strategy for handling no-std context if we do switch to thiserror?

[plafer]

We can't do thiserror for no_std crates unfortunately. I believe the next best alternative is to use displaydoc (as explained in this thiserror thread).

[hackaugusto]

Humm, I didn't know thiserror didn't support no-std. Maybe lets move everything to displaydoc?

[plafer]

For the future: thiserror will support no_std when std::error::Error is moved to core. nightly supports this with the feature flag #![feature(error_in_core)], and here is the tracking issue to stabilize the feature.