Support mandatory recipients

[namtruong]

The change is to allow users to add a mandatoryFor parameter when sending a transaction to Quorum. This feature is useful for use cases where there are requirements for regulatory/observing entities that will have access to the full state of a contract.

Changes

• A new privacy flag called MandatoryRecipients(2). Transactions sent with this enhanced privacy mode will inherit the validations of PartyProtection but not StateValidation. It allows state divergence.
• A transaction sent with this privacy flag will need to include mandatoryFor : [] - which are private TM public keys - otherwise it will be rejected
• Members that are part of mandatoryFor will need to be included in the privateFor otherwise transaction will be rejected.
• /send and /sendsignedtx requests to private TM will include mandatory recipients data
• mandatoryFor members will also be checked against the contracts that the transaction impact. This is achieved by evm simulation that returns a list of ACOTHs and validations performed in Tessera
• Corresponding Tessera updates Support for mandatory recipients tessera#1325

[nicolae-leonte-go]

LGTM

[nmvalera]

LGTM

[Krish1979]

LGTM

[ricardolyn]

+1