[Backport 2.4.x] Add timeout to queryLoki (#8449)

[albscui]

• Add timeout to queryLoki to prevent hanging

• Improve comments for max logs consts

• Get TestQueryLoki passing

• test timeout logic

• server waits for request to timeout instead of sleeping

[codecov]

Codecov Report

Merging #8451 (4de2b03) into 2.4.x (24c925f) will decrease coverage by 0.00%.
The diff coverage is 92.85%.

@@            Coverage Diff             @@
##            2.4.x    #8451      +/-   ##
==========================================
- Coverage   38.78%   38.78%   -0.01%     
==========================================
  Files         425      425              
  Lines      117422   117429       +7     
==========================================
- Hits        45544    45543       -1     
- Misses      62756    62760       +4     
- Partials     9122     9126       +4     

Impacted Files	Coverage Δ
src/server/debug/server/server.go	5.94% <92.85%> (+1.55%)	⬆️
src/internal/task/etcd_service.go	83.82% <0.00%> (-2.95%)	⬇️
src/internal/storage/fileset/storage.go	72.98% <0.00%> (-2.42%)	⬇️
src/internal/storage/fileset/postgres_cache.go	87.62% <0.00%> (-2.07%)	⬇️
src/server/pfs/server/trigger.go	75.00% <0.00%> (-1.79%)	⬇️
src/server/pfs/server/api_server.go	73.74% <0.00%> (-1.31%)	⬇️
src/internal/storage/fileset/postgres_store.go	83.67% <0.00%> (-1.03%)	⬇️
src/server/pfs/server/driver_fsck.go	26.92% <0.00%> (-0.97%)	⬇️
src/server/pps/server/pipeline_controller.go	75.51% <0.00%> (-0.46%)	⬇️
src/internal/collection/postgres_collection.go	81.28% <0.00%> (-0.42%)	⬇️
... and 12 more

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