Reduce scriptSig length for Lelantus transactions

[yura-pakhuchiy]

See trezor/trezor-firmware#1588
Long scriptSig prevents Trezor from signing transactions which uses Lelantus spends as inputs. However Trezor supports long transaction data if it placed after the transaction (similar to Firo coinbase transactions and Zcash privacy transactions). Firo can move Lelantus data from scriptSig to the end of transaction in the next hard fork. Without this change Trezor probably will remove Firo support.

[yura-pakhuchiy]

@reubenyap @levonpetrosyan93 @nopslide consider implementing this ASAP to avoid removal of Trezor support

[reubenyap]

Noted, we are looking into the issue and will discuss this at our upcoming dev meeting on the best way to resolve this.

[psolstice]

As a solution we will move most of the data for lelantus mint/joinspits into transaction v3 payload field (CTransaction::vExtraPayload). This is a field introduced in DASH for proreg data and it should be compatible with hardware wallets. This will make scriptSig compatible with Trezor.

[reubenyap]

This is resolved with #1063