[Config] Remove toml support

[Mirko-von-Leipzig]

As discussed in #650.

Additional considerations:

• Namespace/prefix the environment variables - this includes both to miden as well as component.
• Environment variables should consistent between miden-node start node and miden-node start <component>.

Side refactoring

This is also a good opportunity to refactor the various component crates. They really only expose the component entry-point and nothing else. A simple way to ensure this is to keep everything in lib.rs private and only re-export the entry-point e.g. pub use BlockProducer.

At the moment things are a bit more complex because configuration also lives there. However with the proposed change all configuration should live in the node binary, which is also responsible for converting from config to component structs.

[bobbinth]

Namespace/prefix the environment variables - this includes both to miden as well as component.

Do you mean this should be something like MIDEN_STORE_XXX and MIDEN_BLOCK_PRODUCER_YYY?

[Mirko-von-Leipzig]

Namespace/prefix the environment variables - this includes both to miden as well as component.

Do you mean this should be something like MIDEN_STORE_XXX and MIDEN_BLOCK_PRODUCER_YYY?

Yeah. Because we will up with multiple XXX_ENDPOINT for example. Tbh the MIDEN_ prefix is unlikely to be useful but I do worry about collisions.