Proto: change consensus_rights_delay from 5 to 2

Context

This MR changes consensus_rights_delay from 5 to 2 (see %Preserved Cycles Rework).

This MR is based on !11629 (merged).

Manually testing the MR

• change consensus_rights_delay from 2 to 1 for Sandbox (in /src/proto_alpha/lib_protocol/raw_context.ml at L1197 and src/proto_alpha/lib_parameters/default_parameters.ml at L341)
• activate the previous protocol following the instructions from https://tezos.gitlab.io/developer/proposal_testing.html:

$ ./scripts/user_activated_upgrade.sh src/proto_alpha 8
$ make
$ ./src/bin_node/octez-sandboxed-node.sh 1 --connections 0 &
$ eval $(./src/bin_client/octez-init-sandboxed-client.sh 1)
$ octez-activate-018-Proxford

• bake for 8 blocks to activate proto_alpha:

octez-client bake for --minimal-timestamp

• check that baking_rights are computed for the next cycle only:

octez-client rpc get /chains/main/blocks/head/helpers/baking_rights?cycle=3

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