Use version 2 of Irmin proofs everywhere

Context

This closes #3141 (closed) by changing the types of Irmin proofs in SCORU. Note that nothing is done about TORU.

Note: In the process it became apparent that tezos-node was taking to long to compute the schema of the more complicated proofs. Therefore the MR also contains a change in the type Sc_rollup_originate manager_operationas well as the related Sc_rollup_operations.originate

Manually testing the MR

dune exec tezt/tests/main.exe -- --file mockup.ml

and

dune exec tezt/tests/main.exe -- --file RPC_test.ml

will test the issues with encoding

Checklist

• Document the interface of any function added or modified (see the coding guidelines)
• Document any change to the user interface, including configuration parameters (see node configuration)
• Provide automatic testing (see the testing guide).
• For new features and bug fixes, add an item in the appropriate changelog (docs/protocols/alpha.rst for the protocol and the environment, CHANGES.rst at the root of the repository for everything else).
• Select suitable reviewers using the Reviewers field below.
• Select as Assignee the next person who should take action on that MR