[DO NOT MERGE] KAFKA-10199: Add task updater metrics

[guozhangwang]

Should only be reviewed after https://github.com/apache/kafka/pull/12387.

Needs discussion on KIPs. And also we should only merge this PR after the whole integration is done.

I propose adding the following metrics to state updater:

• restoring-active-tasks: count
• restoring-standby-tasks: count
• paused-active-tasks: count
• paused-standby-tasks: count
• idle-ratio: percentage
• restore-ratio: percentage
• checkpoint-ratio: percentage // idle-ratio + restore-ratio + checkpoint-ratio should == 1
• restore-records-total: count
• restore-records-rate: rate
• restore-call-rate: rate

And also deprecate the following metrics in stream thread:

• poll-ratio: percentage
• standby-process-ratio: percentage

Committer Checklist (excluded from commit message)

• [ ] Verify design and implementation
• [ ] Verify test coverage and CI build status
• [ ] Verify documentation (including upgrade notes)

[guozhangwang]

@cadonna please lmk wdyt about the proposed metric changes in the descriptions.

[guozhangwang]

Closing this PR to rebase and create a new PR later.