Configurable Auth Rules

There are important and potentially dangerous actions in Indy which require a quorum of signers (Trustees, Stewards, etc.).

For example, as a trustee of an Indy Network, the network should require other trustees to sign administrative transactions I want to sponsor so that I am confident that no single trustee can abuse the network. All transactions that require a trustee role should require multiple trustee signatures. Specifically:

• Add a trustee
• Remove a trustee
• Add a steward
• Revoke the role of steward
• Demote a consensus node
• Send an upgrade transaction to the ledger

This feature can be applied not only for trustees and adopted for any role supported by the indy-node.