feat: instrument worker with OpenTelemetry

[sudo-suhas]

• Add Stats(...) method to JobProcessor to allow tracking counts of active and dead jobs by job type.
• Add JobProcessor middleware for OpenTelemetry instrumentation.
• Add middlewares to handlers for dead job managers's endpoints.
• Add histogram compass.worker.jobs.enqueue.duration with the following attributes:
  • job.types: ["index-asset", "delete-asset"]
  • operation.success: true/false
• Add gauge compass.worker.active_jobs with the following attributes:
  • job.type: index-asset/delete-asset
• Add histogram compass.worker.job.dequeue.latency with the following attributes:
  • job.type: index-asset/delete-asset
• Add histogram compass.worker.job.process.duration with the following attributes:
  • job.type: index-asset/delete-asset
  • job.attempt_number: 1/2
  • job.status: done/dead/retry
  • operation.success: true/false
• Add gauge compass.worker.dead_jobs with the following attributes:
  • job.type: index-asset/delete-asset

[coveralls]

Pull Request Test Coverage Report for Build 5781397882

• 69 of 96 (71.88%) changed or added relevant lines in 3 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.2%) to 87.291%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
pkg/worker/pgq/pgq_processor.go	21	27	77.78%
internal/workermanager/worker_manager.go	30	51	58.82%
<!--	Total:	69	96	71.88%	-->

Files with Coverage Reduction	New Missed Lines	%
internal/workermanager/worker_manager.go	1	70.59%
<!--	Total:	1		-->

Totals
Change from base Build 5734607831:	-0.2%
Covered Lines:	6161
Relevant Lines:	7058

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💛 - Coveralls