[Refactor] Organize methods to get data for ServiceManager deploy

[jmoreira-valory]

Organize the following methods from service.py:

get_deployment_payload
get_deployment_with_recovery_payload
get_poly_safe_deployment_payload

get_reuse_multisig_payload
get_reuse_multisig_with_recovery_payload
get_reuse_poly_safe_multisig_payload

Suggetstion: move the logic to respective contracts, like done in get_poly_safe_deployment_payload.

[DavidMinarsch]

Still relevant — the refactor is mostly outstanding. Current state:

• get_deployment_payload (autonomy/chain/service.py:71) and get_deployment_with_recovery_payload (:81): simple deploy-payload formatters, no contract dependency. Could stay where they are or move to a helper module — low value to move.
• get_poly_safe_deployment_payload (:91): already delegated to the contract via registry_contracts.poly_safe_creator_with_recovery_module.get_service_manager_deploy_data(...). This is the exemplar cited in the issue.
• get_reuse_multisig_payload (:709) and get_reuse_multisig_with_recovery_payload (:849): still orchestrate directly across gnosis_safe + multisend contracts from service.py. These are the real targets — add a get_reuse_multisig_payload classmethod on the gnosis_safe contract package that takes the list of new owners and returns the multisend tx_hash / signatures hex, then service.py just calls through.
• get_reuse_poly_safe_multisig_payload (listed in issue body): doesn't exist in the codebase; was speculative.

Keeping open as a tracked refactor — mostly a matter of moving the two get_reuse_multisig_* bodies behind the gnosis_safe contract API.