Balancing algorithm.

Inputs:

• Transaction inputs
• Transaction outputs
• Transaction minted value

Additionally:

• Set of additional UTxOs which can be spent
• Collateral UTxO
• Change address

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

The algorithms used to select inputs & produce change outputs are defined in CoinSelection.

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

There are also transaction 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. Any over approximation (above the actual required fees), leads to generation of change output (besides those generated by coin selection) by makeTransactionBodyAutoBalance. This new change output may fail minimum ada requirement, in which case we iterate with increased fee approximate.

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).