add consensus/protocol version

[tzemanovic]

Describe your changes

based on #4259

Added CONSENSUS_VERSION file in the root with the upcoming version 1. This is exposed in namada_core::consensus_version as well as returned in ABCI /abci_info response in the app_version field ("The application protocol version." in ABCI).

diff for review https://github.com/anoma/namada/pull/4524/files/a8325c5fe84dfab92b9b28fcf0549826cb357287..150247bc9a5905c2abda867a592cd68113ffbe6a

Checklist before merging

• If this PR has some consensus breaking changes, I added the corresponding breaking:: labels
  • This will require 2 reviewers to approve the changes
• If this PR requires changes to the docs or specs, a corresponding PR is opened in the namada-docs repo
  • Relevant PR if applies:
• If this PR affects services such as namada-indexer or namada-masp-indexer, a corresponding PR is opened in that repo
  • Relevant PR if applies:

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 0.00%. Comparing base (a8325c5) to head (1073455).
Report is 29 commits behind head on main.

Additional details and impacted files

@@     Coverage Diff      @@
##   main   #4524   +/-   ##
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[sug0]

if you want you can use a doc attribute, which avoids the extra whitespace,

#[doc = "Get the current consensus version"]

[mergify]

This pull request has been removed from the queue for the following reason: checks failed.

The merge conditions cannot be satisfied due to failing checks:

• ❌ test-e2e (1)
• ❌ test-e2e (2)
• ❌ test-e2e (3)
• ❌ test-e2e (4)

You may have to fix your CI before adding the pull request to the queue again.
If you update this pull request, to fix the CI, it will automatically be requeued once the queue conditions match again.
If you think this was a flaky issue instead, you can requeue the pull request, without updating it, by posting a @mergifyio requeue comment.

[mergify]

Hey @tzemanovic, your pull request has been dequeued due to the following reason: CHECKS_FAILED.
Sorry about that, but you can requeue the PR by using @mergifyio requeue if you think this was a mistake.