Ethan Reesor authored Jun 01, 2022 and Ben Stolman committed Jun 01, 2022

Closes AC-1572. `go build ./tools/cmd/debug` and then:
- Marshal a transaction: `debug encode transaction '{...}'` (argument must be a transaction)
- Hash a transaction: `debug encode transaction --hash '{...}'` (argument must be a transaction)
- Marshal a header: `debug encode transaction header '{...}'` (argument must be a transaction header)
- Hash a header: `debug encode transaction header --hash '{...}'` (argument must be a transaction header)
- Marshal a body: `debug encode transaction body '{...}'` (argument must be a transaction body)
- Hash a body: `debug encode transaction body --hash '{...}'` (argument must be a transaction body)
- Marshal a signature: `debug encode signature '{...}'` (argument must be a signature)
- Hash a signature: `debug encode signature --hash '{...}'` (argument must be a signature)
- Finalize a signature: `debug sign '{...}' <private key>` (first argument must be a signature)

When finalizing a signature, the first argument _must_ include the following fields:
- `type` - the signature type as a string, e.g. `"ed25519"`
- `signer` - the URL of the signer as a string, e.g. `"acc://ethan"`
- `signerVersion` - the version of the key page, or 1 for lite token accounts
- `transactionHash` - the hash of the transaction being signed

When initiating a transaction, the signature _must_ include the timestamp field. To initiate a transaction:
- Calculate the signature metadata hash with `debug encode signature --hash <signature metadata>`. The signature metadata is **all** of the signature fields except for `signature` and `transactionHash`.
- Use that as the `initiator` field of the transaction header.
- Calculate the transaction hash with `debug encode transaction --hash <transaction>`.
- Add that as the `transactionHash` field of the signature.
- Finalize the signature with `debug sign <incomplete signature> <private key>`

You may be able to omit fields without `debug` raising an error, but that will almost certainly produce an invalid signature and/or transaction.

**Note:** PowerShell is dumb and forces you to escape all of the quotes even within quotes. For example, `{"type": "foo"}` has to be passed as `'{\"type\": \"foo\"}'`.

## Review Checklist

**If any item is not complete, the merge request is not ready to be reviewed and must be marked `Draft:`.**

- [x] The merge request title is in the format `<change type>(<change scope>): <short description> [<task id>]`
  - For example, `feat(cli): add QR code generation [AC-123]`
  - For details, see [CONTRIBUTING.md](/CONTRIBUTING.md)
- [x] The description includes `Closes <jira task ID>` (or rarely `Updates <jira task ID>`)
- [~] The change is fully validated by tests that are run during CI
  - In most cases this means a test in "validate.sh"
  - In some cases, a Go test may be acceptable
  - Validation is not applicable to things like documentation updates
  - Purely UI/UX changes can be manually validated, such as changes to human-readable output
  - For all other changes, automated validation tests are an absolute requirement unless a maintainer specifically explains why they are not in a comment on this merge request
- [x] The change is marked with one of the validation labels
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## Merge Checklist

- [ ] CI is passing
- [ ] Merge conflicts are resolved
- [ ] All discussions are resolved

Related to AC-1572