Refactor kairos-tx

[koxu1996]

I extracted great improvements of kairos-tx done by @Avi-D-coder in Trie integration, to reduce clutter in his PR.

List of changes:

• Now all structures - Deposit, Withdrawal, Transfer, SigningPayload - can be created with flexible constructor. Thus helpers.rs got removed.
• Now DER encoding/decoding is part of SigningPayload.
• Updated Nix e2e test to use 2 different account for deposit and withdrawal, also fixed nonces.
• Added Rust e2e test for encoding payloads.

One additional change that I made myself is to allow cloning the base fields, so we can extract nonce/amount/public-key without taking ownership of full transaction - 9fc5a00.

[github-actions]

File	Coverage
All files	63%	✅
kairos-server/src/routes/deposit.rs	86%	✅
kairos-server/src/routes/transfer.rs	73%	✅
kairos-server/src/routes/withdraw.rs	91%	✅
kairos-test-utils/src/cctl/parsers.rs	66%	✅
kairos-crypto/src/implementations/casper.rs	3%	❌
kairos-server/tests/transactions.rs	83%	✅
kairos-server/src/config.rs	0%	❌
kairos-server/src/errors.rs	16%	❌
kairos-server/src/utils.rs	22%	❌
kairos-tx/src/asn.rs	65%	✅
kairos-tx/src/error.rs	0%	❌
kairos-test-utils/src/cctl.rs	87%	✅
kairos-test-utils/src/kairos.rs	95%	✅

Minimum allowed coverage is 60%

Generated by 🐒 cobertura-action against 9fc5a00

[Rom3dius]

Looks good to me. I'm sure I'm missing context here, but why the name "der_encode" and "der_decode"?

Also these github actions are out of control, take far to long to run.

[koxu1996]

@Rom3dius Thanks! Let me provide you context 😉 Schema for Kairos transaction is defined as ASN.1:

TxSchema DEFINITIONS AUTOMATIC TAGS ::= BEGIN

  -- Basic types.
  PublicKey ::= OCTET STRING
  Amount ::= INTEGER (0..18446744073709551615)

  Transfer ::= SEQUENCE {
    recipient PublicKey,
    amount Amount,
    ...
  }

Notably it's fully abstract syntax - there is no definition how those should be converted from and to bytes. However, ASN.1 is closely associated with multiple sets of encoding rules: BER, DER, CER, and others. DER-encoding is the one we are using, as it is fully deterministic, so we can have the exact same bytes representation that is implementation agnostic.

[Avi-D-coder]

Lgtm

[marijanp]

You did not address the comments I left about some of the changed files in Avi's PR:

• Removing the Nonce from deposits
• An explanation for why the payloads and signatures the way they changed in the end-to-end test

[koxu1996]

@marijanp I believe that simple change in Nix e2e tests was explained 3 days ago. You are usually not closing PR discussions that you started, so should I wait for you to click "resolve conversation"?

Your objectives about nonce in schema are not relevant here: this PR is basically refactoring API of schema, but not changing schema itself.