GH-33283: [Dev][Archery][Crossbow] Fix task URL fallback before CI ru…

[limadog9]

Rationale for this change

Closes #33283.

When a Crossbow task has not published a build link yet, report badges currently fall back to the source branch. This makes the CI run harder to find while it is starting.

What changes are included in this PR?

Fall back to the branch-filtered GitHub Actions listing or Azure Pipelines’ latest build for the branch when no build link is available after the existing optional wait. Keep direct build links as the first choice and retain the source-branch fallback for other CI providers. Escape branch names in query parameters.

Are these changes tested?

Added regression coverage for provider fallbacks, direct-link precedence, status refresh outcomes, escaped branch names, and .git remotes. Five regression cases fail with the original implementation and pass with the fix.

• Full Archery unit suite: cd dev/archery && python -m pytest -q archery — 132 passed, 1 skipped (integration test disabled by default).
• Python formatting and lint checks pass for both changed files using the repository configuration and hook versions.
• archery docker check-config and archery crossbow check-config pass.

Are there any user-facing changes?

Crossbow report badges point to the relevant CI build listing while the task’s direct build link is unavailable. No public API changes.

• GitHub Issue: [Dev][Archery][Crossbow] Comment report bot uses the wrong URL if task run has not started  #33283

[github-actions]

⚠️ GitHub issue #33283 has been automatically assigned in GitHub to PR creator.