AggLayer: Normalize storage slot naming

[Fumuran]

This tiny PR updates some of the storage slot names, namely:

• miden::agglayer::let and miden::agglayer::let::* were renamed to have additional bridge after agglayer: miden::agglayer::bridge::let to make all bridge related storage slot consistently have bridge in their names.
• miden::agglayer::faucet and miden::agglayer::faucet::conversion_info_{1, 2} storage slots were renamed to miden::agglayer::bridge::id and miden::agglayer::bridge::conversion_info_{1, 2}. While being the storage slots of the faucet, these slots store the bridge data, so the new name should represent the contents more clearly.

Closes: #2356

[mmagician]

Thanks for taking this on! Unfortunately I think this is one of those bike-sheddeable PRs, so let me go right at it 😁

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There are some slots in bridge_config.masm, of which I think one deserves a rename (of the last component - I'd drop miden prefix from all of them as outlined in the other comments above):

const GER_STORAGE_SLOT=word("miden::agglayer::bridge::ger")

I'd change the name to indicate it's a map.

Regarding admin / ger_manager - we might want to be consistent w.r.t. this holding an account ID, similarly to bridge_id.
So maybe admin_id etc.? Alternatively, suffix all of them with _account_id instead for extra clarity.

[mmagician]

as per the docs, we should follow:

project_name::component_name::slot_name

Here, I would make two modifications:

• drop miden altogether (from all agglayer storage slots)
• use bridge or faucet depending on which component this belongs to (e.g. particular one belongs to the faucet, but describes the bridge account ID. So overall I'd keep it as agglayer::faucet::bridge_id)