[broker][monitoring] add per-subscription EntryFilter metrics

[tjiuming]

Fixes https://github.com/apache/pulsar/issues/16596

Motivation

add per-subscription EntryFilter metrics for PersistentTopic and NonPersistentTopic.

Modifications

Add the following metrics to Prometheus:

1. pulsar_subscription_through_filter_msg_count
2. pulsar_subscription_filter_accepted_msg_count
3. pulsar_subscription_filter_rejected_msg_count
4. pulsar_subscription_filter_rescheduled_msg_count

Add the following metrics to admin-api:

1. throughEntryFilterMsgs
2. entryFilterAccepted
3. entryFilterRejected
4. entryFilterRescheduled

Documentation

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[tjiuming]

@eolivelli @michaeljmarshall PTAL

[tjiuming]

@michaeljmarshall many thanks for you review! I've resolved all the suggestions, PTAL

[michaeljmarshall]

@tjiuming - thanks! Do you feel strongly about keeping Msgs in the admin stats output, or can we change it to MsgCount? I like the latter because it matches the prometheus metric exactly then.

[tjiuming]

@tjiuming - thanks! Do you feel strongly about keeping Msgs in the admin stats output, or can we change it to MsgCount? I like the latter because it matches the prometheus metric exactly then.

it makes sense, and I've resolved them

[michaeljmarshall]

Thanks @tjiuming! Great work!