Improve rewire-pipeline error handling for disabled repos/pipelines

[brianaj]

This PR merges external PR #1465 from @georgy-gorelko which improves error handling and monitoring for the rewire-pipeline command.

Summary

Comprehensive improvements to ADO pipeline rewiring with better error handling, especially around disabled repositories and branch policy checks. Fixes issues introduced in v1.19.0.

Key Changes

1. Fixed Branch Policy Check with Prefixed Repo Names

• Now uses repository ID directly when available instead of just name
• Prevents 404 errors during rewiring for classic pipelines with prefixed names
• Smart fallback: uses ID if available, otherwise looks up by name

2. Disabled Repository Handling

• Checks if repository is disabled before attempting operations
• Skips pipeline rewiring entirely for disabled repos with clear warnings
• Prevents unnecessary API calls that would fail
• Returns proper status (true/false) to indicate success/skip

3. Pipeline Disabled Check

• New IsPipelineEnabled() method checks queueStatus field
• Prevents 400 Bad Request errors when trying to queue builds on disabled pipelines
• Clear warning messages when pipeline is disabled

4. Fixed Misleading Success Messages

• Changed RewirePipelineToGitHub to return bool instead of void
• Only logs success when rewiring actually happened (not when skipped)
• Caller checks return value before showing success message

5. Monitor Timeout Display

• Only shows timeout minutes in dry-run mode (where it's relevant)
• Updated description: "(Dry-run mode only)"
• Custom Log() override in RewirePipelineCommandArgs excludes MonitorTimeoutMinutes

6. Caching Improvements

• Enhanced cache to store both ID and disabled status
• 404 responses treated as disabled repos and cached to avoid repeated calls
• Reduces redundant API calls

Test Coverage

Excellent test coverage with 11 new tests:

• IsPipelineEnabled tests (4 tests)
• Branch policy tests (3 tests)
• Rewiring tests (3 tests)
• Pipeline test service (1 test)

Testing

• All 1029 tests passing
• Comprehensive coverage of disabled repo/pipeline scenarios

Closes #1465

cc: @georgy-gorelko

[github-actions]

Unit Test Results

    1 files      1 suites   10m 25s ⏱️
1 028 tests 1 028 ✅ 0 💤 0 ❌
1 029 runs  1 029 ✅ 0 💤 0 ❌

Results for commit 25dd045.

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
ado2gh	71%	70%	737	➖
Octoshift	84%	74%	1818	✔
bbs2gh	83%	78%	663	✔
gei	81%	73%	608	✔
Summary	81% (7942 / 9824)	74% (1956 / 2657)	3826	✔