Review error handling

[fabiooshiro]

We should verify the status codes returned by our endpoints.

Eg.:

rollups-espresso-reader/internal/espressoreader/espressoreader_service.go

Line 147 in a1ac77c

slog.Error("could not read body", "err", err)

This common case should also be checked in other internal functions:

rollups-espresso-reader/internal/espressoreader/espresso_helper.go

Line 25 in a1ac77c

slog.Error("error making http request", "err", err)

Just a workaround:

rollups-espresso-reader/internal/espressoreader/espresso_helper.go

Line 26 in ea8cda0

return "" // it's not the best way to do it