Integrate InstantSend support in Firo Electrumx #4
Description
Add InstantSend support to FIRO Electrum.
Can be adapted from this commit
Need to investigate if changes needed for Electrumx. Electrumx forms the basis of our mobile wallets and FiroDEX so having InstantSend support allows faster swaps and anonymization since it doesn't need to wait for confirmation.