Fee calculator: allow setting count of each input/output type

[Kixunil]

Instead of assuming whole transaction is of single input/output type allow the user to set count for each input and output type so that fees can be calculated for any transaction (including LN).

[bitschmidty]

@Kixunil thanks for the suggestion!

Do you have some JS skills and is this an effort youd like to help us with?

[Kixunil]

Frankly I hate JS but I occasionally do write it. This is not high-priority for me now (already calculated manually what I needed) but it may happen that I write a PR one day. :) If someone else wants it too better not wait for me.