Break off cli into a self-contained binary

[samlaf]

Right now cli is tied to operator (it constructs an operator struct and uses it to register). This is bad because it means the operator has to take the eigenlayer operator ecdsa key as input, which goes against our new guidelines.

Furthermore, breaking the cli off into a self-contained binary will make it reusable by other AVS teams.

Action items

• refactor cli into its own binary
• remove ecdsa key from operator struct
• move cli to https://github.com/Layr-Labs/eigenlayer-middleware-offchain and make middleware-offchain a submodule of inc-sq so that we can use it here