Port inline multisig changes from eosio.contracts

[arhag]

These changes (EOSIO/eosio.contracts@v1.8.3...9895b08) were lost in the transition from eosio.contracts to mandel-contracts, which then was carried forward into eos-system-contracts and reference-contracts.

We want to capture that functionality in the main branch of reference-contracts.

Some of the changes may only be there to workaround CDT issues that are already fixed. If there are simplifications in the code possible while maintaining the same behavior in the modified eosio.msig contract by assuming CDT v3.0.0 or later can be used, then go ahead and make those simplifications.

In addition, make sure that the eosio.wrap contract also uses inline actions instead of deferred transactions.