Rework to check that only one option is passed to retrieve the amount of the transaction

Sub-task of #213 (closed)

Way to restrict amount, amountUD, allSources

• https://gist.github.com/jacobtolar/fb80d5552a9a9dfc32b12a829fa21c0c
• https://stackoverflow.com/questions/37310718/mutually-exclusive-option-groups-in-python-click
• https://github.com/pallets/click/issues/257
• https://github.com/pallets/click/issues/1137

Write tests

• tests