feature: Bubble$ and Bounties

[19dbo91]

As a bounty setter,
I WANT TO set bounties of Bubble$ invited people can complete
SO THAT I can get assistance with tasks

As a bounty setter,
I WANT TO set Rewards I would give to people at a certain Bubble$ cost
SO THAT I can award them with a prize of their choice

AS a bounty getter,
I WANT TO be able to collect bounties
SO THAT I can receive Bubble$

AS a bounty getter,
I WANT TO cash in Bubble$
SO THAT I can receive a reward from the bounty setter