feat: refactor settings

[apoorvsadana]

Refactor the with_settings usage. We need to decide how and where should we read config variables from - env or json. env is easier to to config when hosting but json is more readable. Currently, the usage of with_settings seems to be incorrect in a few places where we read an env after fetching the settings from the provider (https://github.com/karnotxyz/madara-orchestrator/blob/7baf1903b50fb52815fdf5b4e65733ec0076620d/crates/settlement-clients/ethereum/src/lib.rs#L40-L40). This seems incorrect, we need to figure out a coherent approach and implement it.