Add getConvention to IborFutureTemplate


#1

It seems that IborFutureTemplate is the only TradeTemplate implementation which does not have a public getConvention method and both it’s implementing classes have that method. I think it should be added to the interface to be consistent.


#2

Seems reasonable: https://github.com/OpenGamma/Strata/pull/1810


#3

Great, thanks for the addition