Decide the owner and withdrawal model for shared-collateral and multi-payout EvoNodes #5617

Context

• feat(platform)!: support Core v24 masternode identities at protocol version 14 #5227 (protocol version 14, Platform 5.0) already accepts shared-collateral and multi-payout masternodes from Core v24, but Platform has no ownership or reward-withdrawal model for them.
• docs: propose EvoNode Platform reward withdrawals dips#193 (EvoNode Platform reward withdrawals) is open.
• feat(consensus): hold EvoNode shares and multiple payouts behind a new evo_shares deployment dash#7807 puts EvoNode shares and multiple payouts behind a new evo_shares deployment.

Decision needed

Does Platform 5.1 need an owner-identity model for shared and multi-payout EvoNodes (who may withdraw which part of the Platform rewards), or does it wait for dips#193 and the evo_shares deployment? If yes, this becomes a protocol-version-15 feature with a spec; if no, document the current behaviour for operators of such nodes.

Related: #5437 (decode the shared-masternode transaction types 10/11/12).