add work queue metrics for agent and controller-manager

[Garrybest]

Signed-off-by: Garrybest [email protected]

What type of PR is this?
/kind feature

What this PR does / why we need it:
The async worker queue metrics will be registered here. So we should init the package first.

Which issue(s) this PR fixes:
Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Instrumentation: Introduced several metrics(`workqueue_adds_total`, `workqueue_depth`, `workqueue_longest_running_processor_seconds`, `workqueue_queue_duration_seconds_bucket`) for `karmada-agent` and `karmada-controller-manager`.

[RainbowMango]

LGTM.
What's the metrics look like?

[Garrybest]

# HELP workqueue_adds_total Total number of adds handled by workqueue
# TYPE workqueue_adds_total counter
workqueue_adds_total{name="cluster"} 22547
workqueue_adds_total{name="service-export"} 0
workqueue_adds_total{name="work"} 314072
workqueue_adds_total{name="work-status"} 527134
# HELP workqueue_depth Current depth of workqueue
# TYPE workqueue_depth gauge
workqueue_depth{name="cluster"} 0
workqueue_depth{name="service-export"} 0
workqueue_depth{name="work"} 0
workqueue_depth{name="work-status"} 0
# HELP workqueue_longest_running_processor_seconds How many seconds has the longest running processor for workqueue been running.
# TYPE workqueue_longest_running_processor_seconds gauge
workqueue_longest_running_processor_seconds{name="cluster"} 0
workqueue_longest_running_processor_seconds{name="service-export"} 0
workqueue_longest_running_processor_seconds{name="work"} 0
workqueue_longest_running_processor_seconds{name="work-status"} 0
# HELP workqueue_queue_duration_seconds How long in seconds an item stays in workqueue before being requested
# TYPE workqueue_queue_duration_seconds histogram
workqueue_queue_duration_seconds_bucket{name="cluster",le="1e-08"} 0
workqueue_queue_duration_seconds_bucket{name="cluster",le="1e-07"} 0
workqueue_queue_duration_seconds_bucket{name="cluster",le="1e-06"} 0
workqueue_queue_duration_seconds_bucket{name="cluster",le="9.999999999999999e-06"} 17692
workqueue_queue_duration_seconds_bucket{name="cluster",le="9.999999999999999e-05"} 22538

[RainbowMango]

Thanks.
/lgtm
/approve

[karmada-bot]

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