Cardano Updates

# Conflicts:
#	rust/src/utils.rs

Added ref inputs support to inputs builder

Added tx_builder.add_bundled_change_if_needed than takes a max
tokens bundle size parameter. This allows to split the change
output into multiple outputs based on a fixed number of NFTs.

Updated the (admittedly quite stale) example/index.ts and added a
relevant test to example/index.spec.ts