Balancing algorithm.

Inputs:

• Transaction inputs
• Transaction outputs
• Transaction minted value

Additionally:

• Set of additional UTxOs which can be spent
• Collateral UTxO which shouldn't be spent
• Change address

The algorithm should produce sets of inputs and outputs such the total value is input + minted = outputs.

The algorithm used to select inputs is defined in CoinSelection.

Each output should be big enough (contain enough ADA, calculateMinimumUTxO). Algorithm may adjust them to include additional value.

There are also transacton fees which should also be taken into account. We over-approximate the fees, and let makeTransactionBodyAutoBalance balance fees. (We can be more precise here, and only slightly over-approximate, but cardano-api doesn't provide a handy helpers to fill in execution units).

We make the algorithm iterative over the fee over-approximation. In particular, we start off with a small over-approximation, and if tx finalization fails, we increase it. The very first success is returned.

The algorithm should add additional inputs so all inputs have enough value for all (adjusted) outputs.

As usually inputs and outputs don't match equally, the left-over inputs are sent to change address. This output should also be adjusted. (TODO: is it enough to send only non-ADA there?)

Collateral input is needed when scripts are executed, i.e. transaction mints tokens or consumes script outputs.

See evaluateTransactionBalance and makeTransactionBodyAutoBalance (this function balances ADA only and doesn't add inputs, i.e. it calculates the ADA change). This also means that currently, it is unable to put non-ada tokens as return collateral output, so as of now we only support ada only collateral utxo.