Create a UBI component that distributions a constant amount of coin
to each mobile agent every period, drawing from the planner agent's
coin endowment (which currently can run into the negatives).

Allow the planner agent to determine the UBI payment amount.

In more detail:
Convert UBI to have discretized amounts that the planner can choose from, define get_n_actions() to allow the planner’s actions to determine UBI payment amount, and define set_new_period_amt_model() to update the UBI payment amount each period.

Allow the planner and mobile agents to see the position in the UBI cycle
as well as the UBI amount and previous UBI amount.

Track the UBI payment amount of the previous step to use in observations.

Also add additional reset steps (for correctness).

Restrict planner actions so that the agent can only act/modify UBI
on the appropriate day of the cycle.

Also add logging that shows the size of UBI payments used at each
time step.

Create a version of PeriodicBracketTax that does not do lumpsum
redistribution and instead adds revenue to the planner agent's
coin endowment.

Fix bugs after testing UBI and SimpleRevenue components. Both appear
to run and seem in working order.

Require planner to choose a UBI payment amount that its current
coin endowment can pay out without becoming negative.

Also edit the NO-OP operation so that it sets UBI to 0.
(Otherwise, maintaining a UBI rate may drive planner coin
into the negatives.) This may change though.

Reformatted using format_and_lint.sh.