What

The manager_key rpc

Why

see milestone

The service is in a private module, so we first make it public. While we're at it, we make it public in all versions we might need in the future.

We test using curl because the octez-client doesn't provide what's needed. A proper test (with a non null value) will require bootstrap accounts.

And now that the services are public in the plugin, we can also import balance instead of copying it.

dune exec etherlink/tezt/tests/main.exe -- tezlink manager_key

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