add more information to error logs by, when possible, including the variables that caused the errors
add more information to error logs by, when possible, including the variables that caused the errors

Summary: Korbit pointed out an error they were having with fees they were setting, and I thought it would be useful to add extra information to the error logs

Reviewers: benchan, ben

Reviewed By: ben

Subscribers: ben

Differential Revision: https://phabricator.bitgo.com/D4439

BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS,BitGo/BitGoJS