Add scan metrics for bft disagreement

[nicu-da]

Also include alerts

[ci]

fixes #3206

Pull Request Checklist

Cluster Testing

• If a cluster test is required, comment /cluster_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If an upgrade test is required, comment /upgrade_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a hard-migration test is required (from the latest release), comment /hdm_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a logical synchronizer upgrade test is required (from canton-3.5), comment /lsu_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.

PR Guidelines

• Include any change that might be observable by our partners or affect their deployment in the release notes.
• Specify fixed issues with Fixes #n, and mention issues worked on using #n
• Include a screenshot for frontend-related PRs - see README or use your favorite screenshot tool

Merge Guidelines

• Make the git commit message look sensible when squash-merging on GitHub (most likely: just copy your PR description).

[canton-network-da]

[backport] Reminder

Please consider backporting to the following branches:

• release-line-0.6.8
• release-line-0.6.7
• release-line-0.6.6
• release-line-0.6.5

▶️ Please check the boxes for branches that you wish to backport to and backport PRs will
automatically be created when you merge this PR.

And your PR is currently against base branch: main.

Note: Any PR comment containing [backport] will be considered for auto-backporting upon merge,
you can always add those manually for PRs that did not get these reminders. You can also edit
this comment manually and add more branches that this should be backported to.