Support for decoding TX auxiliary data #1086
Description
There are different possible auxiliary data formats for different eras, and we need to be able to support them all in later eras. We'll also need a common interface type for querying data from it no matter the format.
From the Conway CDDL:
auxiliary_data = shelley_auxiliary_data/ shelley_ma_auxiliary_data/ alonzo_auxiliary_data shelley_auxiliary_data = metadata metadata = {* transaction_metadatum_label => transaction_metadatum} transaction_metadatum_label = uint .size 8 transaction_metadatum = {* transaction_metadatum => transaction_metadatum} / [* transaction_metadatum] / int / bytes .size (0 .. 64) / text .size (0 .. 64) shelley_ma_auxiliary_data = [transaction_metadata : metadata, auxiliary_scripts : [* native_script]] alonzo_auxiliary_data = #6.259( { ? 0 : metadata , ? 1 : [* native_script] , ? 2 : [* plutus_v1_script] , ? 3 : [* plutus_v2_script] , ? 4 : [* plutus_v3_script] } )