[fix][doc] correct configuration name to exposingBrokerEntryMetadataToClientEnabled

[Anonymitaet]

Fix #13336 (review)

I do not fix occurrences in reference-configuration.md because we're optimizing the workflow (trying to generate docs from code automatically for https://pulsar.apache.org/docs/next/reference-configuration)

• doc

[RobertIndie]

The brokerEntryMetadataInterceptors should not appear before V2.10.0. It's the same with #17004

[BewareMyPower]

brokerEntryMetadataInterceptors was introduced since 2.8.0, but enableExposingBrokerEntryMetadataToClient was introduced since 2.10.0.

[Huanli-Meng]

LGTM

[Anonymitaet]

@BewareMyPower
Double check: I've updated enableExposingBrokerEntryMetadataToClient for these versions, is it correct?

[Anonymitaet]

ping @BewareMyPower again :-D

[BewareMyPower]

Could you check this comment?

[Anonymitaet]

@RobertIndie @BewareMyPower thanks for your suggestions!

I've updated this PR based on your comments. The changes are summarized below, PTAL.

1. Keep the following content for 2.8.x and 2.9.x.

## Broker entry metadata

Broker entry metadata is stored alongside the message metadata as a serialized protobuf message.
It is created by the broker when the message arrived at the broker and passed without changes to the consumer if configured.

| Field              | Required or optional       | Description                                                                                                                   |
|:-------------------|:----------------|:------------------------------------------------------------------------------------------------------------------------------|
| `broker_timestamp` | Optional        | The timestamp when a message arrived at the broker (`id est` as the number of milliseconds since January 1st, 1970 in UTC)      |
| `index`            | Optional        | The index of the message. It is assigned by the broker.

If you want to use broker entry metadata for **brokers**, configure the [`brokerEntryMetadataInterceptors`](reference-configuration.md#broker) parameter in the `broker.conf` file.

2. Keep the following content for 2.10.x.

## Broker entry metadata

Broker entry metadata is stored alongside the message metadata as a serialized protobuf message.
It is created by the broker when the message arrived at the broker and passed without changes to the consumer if configured.

| Field              | Required or optional       | Description                                                                                                                   |
|:-------------------|:----------------|:------------------------------------------------------------------------------------------------------------------------------|
| `broker_timestamp` | Optional        | The timestamp when a message arrived at the broker (`id est` as the number of milliseconds since January 1st, 1970 in UTC)      |
| `index`            | Optional        | The index of the message. It is assigned by the broker.

If you want to use broker entry metadata for **brokers**, configure the [`brokerEntryMetadataInterceptors`](reference-configuration.md#broker) parameter in the `broker.conf` file.

If you want to use broker entry metadata for **consumers**:

1. Use the client protocol version [18 or later](https://github.com/apache/pulsar/blob/ca37e67211feda4f7e0984e6414e707f1c1dfd07/pulsar-common/src/main/proto/PulsarApi.proto#L259).
   
2. Configure the [`brokerEntryMetadataInterceptors`](reference-configuration.md#broker) parameter and set the [`exposingBrokerEntryMetadataToClientEnabled`](reference-configuration-broker.md#exposingbrokerentrymetadatatoclientenabled) parameter to `true` in the `broker.conf` file.

3. Remove the following content for versions prior to 2.8.0.

## Broker entry metadata

Broker entry metadata is stored alongside the message metadata as a serialized protobuf message.
It is created by the broker when the message arrived at the broker and passed without changes to the consumer if configured.

| Field              | Required or optional       | Description                                                                                                                   |
|:-------------------|:----------------|:------------------------------------------------------------------------------------------------------------------------------|
| `broker_timestamp` | Optional        | The timestamp when a message arrived at the broker (`id est` as the number of milliseconds since January 1st, 1970 in UTC)      |
| `index`            | Optional        | The index of the message. It is assigned by the broker.

If you want to use broker entry metadata for **brokers**, configure the [`brokerEntryMetadataInterceptors`](reference-configuration.md#broker) parameter in the `broker.conf` file.

If you want to use broker entry metadata for **consumers**:

1. Use the client protocol version [18 or later](https://github.com/apache/pulsar/blob/ca37e67211feda4f7e0984e6414e707f1c1dfd07/pulsar-common/src/main/proto/PulsarApi.proto#L259).
   
2. Configure the [`brokerEntryMetadataInterceptors`](reference-configuration.md#broker) parameter and set the [`exposingBrokerEntryMetadataToClientEnabled`](reference-configuration-broker.md#exposingbrokerentrymetadatatoclientenabled) parameter to `true` in the `broker.conf` file.

4. Ignore updating the versions in red and only updating versions in green since reds are deprecated. Details see Update versioned docs.

cc @momo-jun

[BewareMyPower]

I found another problem when I reviewed this PR but it's not related. I found some versioned docs contain both develop-binary-protocol.md and developing-binary-protocol.md. I compared these two files in version-2.9.1 directory (after applying changes of this PR), they are nearly the same.

2c2
< id: develop-binary-protocol
---
> id: developing-binary-protocol
5c5
< original_id: develop-binary-protocol
---
> original_id: developing-binary-protocol
400a401,425
>  * `properties` → *(optional)* Reserved configuration items
>  * `txnid_most_bits` → *(optional)* Same as Transaction Coordinator ID, `txnid_most_bits` and `txnid_least_bits`
>    uniquely identify a transaction.
>  * `txnid_least_bits` → *(optional)* The ID of the transaction opened in a transaction coordinator,
>    `txnid_most_bits` and `txnid_least_bits`uniquely identify a transaction.
>  * `request_id` → *(optional)* ID for handling response and timeout.
> 
> 
>  ##### Command AckResponse
> 
> An `AckResponse` is the broker’s response to acknowledge a request sent by the client. It contains the `consumer_id` sent in the request.
> If a transaction is used, it contains both the Transaction ID and the Request ID that are sent in the request. The client finishes the specific request according to the Request ID. If the `error` field is set, it indicates that the request has failed.
> 
> An example of `AckResponse` with redirection:
> 
> ```protobuf
> 
> message CommandAckResponse {
>     "consumer_id" : 1,
>     "txnid_least_bits" = 0,
>     "txnid_most_bits" = 1,
>     "request_id" = 5
> }
> 
> ```
461c486
< Lookup can be done with a REST call as described in the [admin API](admin-api-topics.md#look-up-topics-owner-broker)
---
> Lookup can be done with a REST call as described in the [admin API](admin-api-topics.md#lookup-of-topic)

Could we delete the develop-binary-protocol.md?

[Anonymitaet]

@BewareMyPower thank you! Suggest keeping it since there might be potential issues if it's removed.

Besides, keeping it does not cause trouble for doc maintainers since there is only developing-binary-protocol.md (no develop-binary-protocol.md) in version-2.8.x, version-2.9.x, version-2.10.x, master, and versions forward.