Reverts AC-2434. When we attempted to launch the RC3 testnet, the DN claimed it received 8 anchors from BVN 0, but BVN 0 claimed it only produced 3 anchors. Since AC-2434 made changes to how sequence numbers are produced and recorded, we are going to revert (most of) it in the hope that will fix the problem.

35eaa846 shows the net change, roughly. That is, it shows !545, !574, and this MR merged into a single commit. It's not exact because of changes that happened in between.

## 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>`)
- [x] 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
  - ~"validation::ci/cd" for changes validated by CI tests
  - ~"validation::manual" for changes validated by hand
  - ~"validation::deferred" for changes validated by a follow up merge request
  - ~"validation::not applicable" for changes where validation is not applicable

## Merge Checklist

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

Related to AC-2434