Ergonomic MST

[mversic]

Ideas on how can we make MST more ergonomic:

1. All smart contracts for MST should be registered from Executor, i.e. be put in default executor migration
2. I think we need an API to fetch all currently voted for transactions, i.e. pending transactions
3. we need a way to expire MST that have not been active for a while
4. We can define custom instructions for dealing with MST and also have them defined as part of default executor

Additionally, we should consider adding (behind a feature flag "mst") a specialized API to both iroha client and cli for dealing with MSTs.

[mversic]

actually, instead of doing it during executor migration as was suggested in 1. they should be registered in the genesis

[s8sato]

Remaining issues after #5027:

• custom instructions to encapsulate multisig operations
• migrate shell script tests to pytests
• regulate multisig account registrations?
• make the default multisig TTL indefinite?
• TTL in seconds or humantime at CLI?

[mversic]

* [make the default multisig ttl indefinite?](https://github.com/hyperledger/iroha/pull/5027#discussion_r1742874965)

no, there should always be some default non-infinite value

[0x009922]

My comment regarding the client interface: #5027 (comment)

I don't immediately like the idea of having this being included directly into the client. Though, it depends on how much we need to make multisig an official out-of-the-box feature.

As an alternative idea, there could a separate CLI to construct multisig-related instructions in a form of JSON, which then could be supplied to the client:

iroha_multisig register --account .. --weights .. --quorum .. | iroha json transaction

[s8sato]

• Partially resolves Ergonomic MST #4930

Accidentally automatically closed. Reopened

[s8sato]

The following will be addressed after #5217:

• test: recursion test suites
• refactor!: consolidate metadata read/write
• fix: prevent expired/executed orphans
• fix: question existence and format of metadata
• feat!: override TTL per transaction
• feat: pretty list of pending proposals