Tracking: improve handling and correct prioritisation in CLI about foundry HOT 1 OPEN

I think it makes sense to divide this ticket into multiple stages to be able to ship concrete improvements in user experience faster to users.

Short term:

• Investigate, simplify and fix handling of .env (we currently use dotenvy, Clap and Figment)
• Manually track down, index and add missing CLI arguments from (or vice versa):
  • Default + Figment (global foundry.toml / local foundry.toml) configuration
  • Environment variables
• Resolve related bugs and feature requests

Medium term:

• Create a unified standalone abstraction crate using Figment + Clap, should be re-usable by Reth.
  • Define a single source of truth and derive Cast parameters, Figment configuration and Figment environment variables programmatically. It will be difficult for this to be written cleanly in a backwards compatible way.
  • The current implementation has top-level definitions of arguments that are re-used and crate local definitions that are used only locally. This generally makes sense as you do not want to clutter a top-level crate with crate specific implementation details.

Long term:

• Create a unified abstraction crate, optionally using different dependencies or a solution designed from scratch

from foundry.