Split shelley-ma into allegra and mary

[lehins]

This PR splits the package cardano-ledger-shelley-ma into two packages that implement proper eras:

• cardano-ledger-allegra
• cardano-ledger-mary.

It is important to point out that in order to keep this PR as small as possible the test package cardano-ledger-shelley-ma-test is still a thing. That test package will be restructured into separate libraries in the corresponding eras/allegra/ and eras/mary/ directories in a later PR. shelley-ma era also contains the spec, which I am not quite sure yet where it should eventually live, since it does combine the two eras together as one document.

There is no longer a ShelleyMAEra ma c, there are proper types that replace it:

• AllegraEra c
• and MaryEra c.

Conceptually the only thing that is different between the two eras is the support of multi assets by the latter era, therefore the only type that had seen a somewhat impactful change was the TxBody.

There is no longer MATxBody, but two:

• AllegraTxBody
• and MaryTxBody.

Care was take to reduce duplication so, both of those types are backed by the same raw type underneath. This also means that corresponding type class was split as well:

There is no longer ShelleyMAEraTxBody, but instead these two:

• AllegraEraTxBody
• and MaryEraTxBody.

[teodanciu]

This is awesome! Looks good to me, just some minor questions and remarks.

[JaredCorduan]

Looks good, thank you @lehins !

I can't recall why shelleyToAllegraAVVMsToDelete is still around if it is not used...

Is the plan to keep eras/shelley-ma/test-suite for testing? or punt for now and move it later? (I'd love to get my tab-complete on "shel" back 😆 )

[lehins]

Is the plan to keep eras/shelley-ma/test-suite for testing?

Yes, I will split cardano-ledger-shelley-ma-test in a subsequent PR. I've updated the #3171 ticket to reflect it

(I'd love to get my tab-complete on "shel" back laughing )

Unfortunately we'll have to keep cardano-ledger-shelley-ma for a little bit until downstream reflect on these changes. But afterwards we'll definitely be able to get rid of era/shelley-ma folder. One thing I am not certain about is where to put the era/shelley-ma/formal-spec folder, since it crams both Allegra and Mary in there

[JaredCorduan]

Unfortunately we'll have to keep cardano-ledger-shelley-ma for a little bit until downstream reflect on these changes. But afterwards we'll definitely be able to get rid of era/shelley-ma folder. One thing I am not certain about is where to put the era/shelley-ma/formal-spec folder, since it crams both Allegra and Mary in there

IMHO, it is the Mary spec. There is no Allegra spec, you just have to know what parts of the Mary spec to leave out... Maybe we can rename it to the Mary spec and have an appendix about the "Allegra spec".

cc @polinavino @WhatisRT