feat: ledger

[jdutchak]

As part of #345 we have decided to go with our on-chain ledger rather then using another third party ledger.

The key takeaways are:

our own ledger that can store a limited set of data in the on-chain ledger. The ledger is implemented similarly to what EdgeVPN uses.
The ledger can be used to store a CID (content addressable ID) to reference a data that is carried over with the ledger. that for instance can be used to store big files or content that doesn't fit the ledger (see also #345 (comment) )
The ledger can be written only by trusted nodes, but can be read by all nodes of the network
For development, we can also point to an IPFS CID that is then pinned by the oracle nodes. That would allow us to quickly iterate in the short term while we develop a CID system inside our own protocol.
This card is about wrapping up the esperimental PR work in #350 and have it merged in the repository.

Describe alternatives you've considered
Using an external blockchain as a ledger (see discussions in #345)

Acceptance criteria
#350 is wrapped up and merged in the codebase

[mudler]

@jdutchak can you add a description to the PR and have the title reflect what's the changeset? thank you!

It's just because #384 or even #350 have similar title and it's hard to track down when a change went into the code (for release notes, etc).

[mudler]

Changes overall looks good, however:

• Above nitpicks
• Please split the work of ci: Run unit tests in github actions runners #369 in a separate PR, as we don't seem to bring any unit test with these changes, no need to add it here.
• The title and description are copied verbatim from the issue feat: On chain ledger #380 which doesn't add much context. The PR title/description can be improved so that shows the changeset introduced with the PR. Please see https://www.conventionalcommits.org/en/v1.0.0/ for guidance
• The test file added is called e2e but it is introducing unit tests, not e2e tests

[restevens402]

Looks good. Blocks are clean and straightforward. Let's go!

[mudler]

Few changes requested but ignored - some of them are nitpicks, but I think some of these needs to be addressed before merging:

• please split the release note changes to a separate PR
• update the PR title/description to match the changeset
• brittle pointer dereference

Otherwise looks good - nice job!

[mudler]

re: commitlint, if you rebase on top of test now that error should be gone, the CI checks now PR title/description rather then single commits

[jdutchak]

done

[mudler]

Looking good! great job 🥳