[2.10] Pending jobs in coordinator queue + test fix

[meiravgri]

MOD-12069 Multi threaded section
MOD-12788 Number of pending jobs in coordinator queue

Backport of #7596 + #7641 to 2.10 branch. Exposes coord_high_priority_pending_jobs metric in INFO MODULES multi_threading section.

---

Note

Adds coord_high_priority_pending_jobs to INFO MODULES and introduces FT.DEBUG COORD_THREADS (pause/resume/is_paused), with corresponding coordinator/threadpool plumbing and tests.

• Metrics:
  • Add coord_high_priority_pending_jobs to MultiThreadingStats and expose it in INFO MODULES via GlobalStats_GetMultiThreadingStats and AddToInfo_MultiThreading.
  • Implement ConcurrentSearchPool_HighPriorityPendingJobsCount() to report coordinator high-priority queue size.
• Coordinator Debug Controls:
  • New FT.DEBUG COORD_THREADS subcommand (PAUSE | RESUME | IS_PAUSED), registered in coordCommands and listed in coord/src/debug_command_names.h.
  • Add helpers ConcurrentSearch_isPaused(), ConcurrentSearch_pause(), ConcurrentSearch_resume().
• Tests:
  • Extend wait_for_condition with timeout param.
  • Add cluster tests verifying coord_high_priority_pending_jobs for FT.SEARCH, FT.AGGREGATE, and FT.CURSOR READ when coordinator threads are paused.
  • Update multi-threading stats tests to assert presence of new fields.

^{Written by Cursor Bugbot for commit 8645d38. This will update automatically on new commits. Configure here.}

[codecov]

Codecov Report

❌ Patch coverage is 82.05128% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 89.42%. Comparing base (4e5b0f4) to head (8645d38).
⚠️ Report is 1 commits behind head on 2.10.

Files with missing lines	Patch %	Lines
coord/src/debug_commands.c	71.42%	4 Missing ⚠️
src/concurrent_ctx.c	86.95%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             2.10    #7744      +/-   ##
==========================================
- Coverage   89.46%   89.42%   -0.04%     
==========================================
  Files         210      210              
  Lines       36087    36126      +39     
==========================================
+ Hits        32284    32306      +22     
- Misses       3803     3820      +17     

Flag	Coverage Δ
flow	84.08% <82.05%> (-0.17%)	⬇️
unit	42.09% <12.82%> (-0.04%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.