Add PlutusTx version

[zmrocze]

Let's add the PlutusTx version, without changing the onchain flake, inside the same haskell onchain project.
Plutus is available there, with compile and serializeCompiledCode one can go from code to more-or-less script bytestring. Then the text envelope file - best if can be created with ply with ready library function - if not could be created ad hoc as its just a json file (with aeson).

I still think cardano-api among deps would be beneficial as its likely the first dependency a user is going to add himself, but its not indispensible.

Probably PlutusTx onchain should exactly mimic Plutarch, right? So that the two script exporters are interchangable and offchain and frontend are blind to the difference.

[gnumonik]

If we want interchangeable exporters/importers, we can either:

• 1. Erase type information from the Ply output, thereby transforming it into a cardano-api style TextEnvelope (Actually we wouldn't be erasing anything, we'd just add some fields to the JSON so that ply output can be read without ply-ctl on the frontend)
• 2. Implement some machinery to serialize type information when writing PlutusTx scripts such that they're compatible w/ ply-ctl

I think that today I'm going to try to implement 1) and we can discuss whether we want to put in the time to implement 2), which would probably be better but take a lot longer to implement.