Feature: Add to the txs cli, a command to set a multisig

[dboreham]

From @hemulin

Description:
As part of the v7 codebase, we have a multisig capabilities out-of-the-box. An account can be set as a multisig. The Libra_framework supposedly has the methods available to be called, all is missing is a CLI command that will call them.

As inspiration, one can look at the Community wallet awakening process. An example command would be:

libra txs community gov-init -a SIGNER_1_ADDRESS -a SIGNER_2_ADDRESS -a SIGNER_N_ADDRESS -n 2

Where the -n flag is the minimum quorum of signers to approve a tx.

This command I believe is calling

libra-framework/tools/txs/src/txs_cli_community.rs

Line 347 in 7fe1ba1

impl InitTx {

Down the stack, I think it also calls the multisig creation

libra-framework/framework/cached-packages/src/libra_framework_sdk_builder.rs

Line 1651 in 7fe1ba1

pub fn multisig_account_create(

The task is to add to the txs cli tool, a command that will take a similar input, signer addresses and a quorum, will submit this onchain, and report back once completed.

Additionally, while there, CLI addition to manage the multisig (add/remove signers) would also be helpful.

CLI to generate txfer transactions from such a multisig account maybe something like:
libra txs propose --recipient 0x015D24D20F115C4A8224651C9F345EBA8E239DD8E9C05DE62AD0B0048473B01D --amount 100

[soaresa]

@dboreham , the feature I'm implementing for issue #227 is related to this issue (#247). The changes in #227 will modify the authority assignment flow and the multisign account setting process. This will impact how the CLI commands for multisig setup and management are implemented.