[improve][broker]prevent partitioned metadata lookup request when broker is closing

[HQebupt]

Motivation

Inspired by #17085
When the leader broker is closing, and the client will reconnect and redo lookup, resulting in unexpected results.

@codelipenghui
Looks like we also need to check other cases (e.g. handleConnect)
If the broker is shutting down, we should also prevent new connections.

Therefore, it is necessary to check the status of the broker when handling requests, including connect\lookup\partitioned metadata.

The following is the interaction workflow between consumer and broker.

Consumer -> Broker: CONNECT
Broker -> Consumer: CONNECTED
Consumer -> Broker: PARTITIONED_METADATA
Broker -> Consumer: PARTITIONED_METADATA_RESPONSE
Consumer -> Broker: LOOKUP
Broker -> Consumer: LOOKUP_RESPONSE
Consumer -> Broker: SUBSCIBE
Broker -> Consumer: SUCCESS
Consumer -> Broker: FLOW
Broker -> Consumer: MESSAGE
Consumer - Broker: ACK

The following screenshot is the interaction workflow between producer and broker.

Modifications

• Check Pulsar Service state when handle connection and partitioned metadata request.

Verifying this change

• Make sure that the change passes the CI checks.

This change is a trivial rework / code cleanup without any test coverage.

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (no)
• The public API: (no)
• The schema: (no)
• The default values of configurations: (no)
• The wire protocol: (no)
• The rest endpoints: (no)
• The admin cli options: (no)
• Anything that affects deployment: (no)

Documentation

Check the box below and label this PR (if you have committer privilege).

Need to update docs?

• doc-not-needed

[HQebupt]

/pulsarbot run-failure-checks

[codelipenghui]

Please add a test to cover the new changes.

[HQebupt]

@codelipenghui PTAL when you are available.

[michaeljmarshall]

LGTM

[AnonHxy]

LGTM with minor comment