Make the translation between asset types configurable

[alvarogarcia7]

Make the translation configurable, to allow for different assets to be translated into other assets

Right now,

r4-automator	robot-advisor
Fund	XDTO(transferrable=false)
Cash	XDTO(transferrable=true)

[alvarogarcia7]

For now, this will be solved with the 'Contribute' operation, which transforms Cash into funds