Fee Estimation ported from bitcoin core
Copy over the code for fee estimation from stratis repo
This PR was initially started by @AndrewZvvv
stratisproject/StratisBitcoinFullNode#1486
And continues here and later by @zeptin
stratisproject/StratisBitcoinFullNode#4040
Due to the link between repos now removed the code probably needs to be copied over
Fee Estimation ported from bitcoin core
Copy over the code for fee estimation from stratis repo
This PR was initially started by @AndrewZvvv
stratisproject/StratisBitcoinFullNode#1486
And continues here and later by @zeptin
stratisproject/StratisBitcoinFullNode#4040
Due to the link between repos now removed the code probably needs to be copied over