[improve][common] Make Bookkeeper metadata options configurable

[lhotari]

Motivation

PIP-45 related PRs #12770 and #13296 introduced changes in Pulsar and Bookkeeper configuration for Pulsar so that Pulsar Metadata driver is used for metadata operations in the bookkeeper client (in broker) and in the bookkeeper server (the bookies).
It would be good to have a way to opt-out of this change and configure Pulsar and Bookies without Pulsar Metadata store and use Zookeeper directly.

This PR will allow to use Bookkeeper defaults by setting export BK_METADATA_OPTIONS=none.

If one would want to configure Bookies without Pulsar Metadata, it is necessary to configure
metadataServiceUri in bookkeeper.conf and bookkeeperMetadataServiceUri in broker.conf.

For example bookkeeper.conf

metadataServiceUri=zk://<zk_node_1>:2181/ledgers,zk://<zk_node_2>:2181/ledgers,zk://<zk_node_3>:2181/ledgers

The main purpose of this PR is to make it easier to compare the behavior of Pulsar when using Pulsar Metadata driver for Bookkeeper compared to using Zookeeper directly. It is not necessary make BK_METADATA_OPTIONS configurable to achieve this. However it's better to have an option to control it since that could prevent misconfiguration in cases where it is desired to not use Pulsar metadata driver.

The additional benefit of being able to override BK_METADATA_OPTIONS is that the Pulsar Metadata driver classes wouldn't get loaded at all when they aren't used.

Modifications

Make BK_METADATA_OPTIONS configurable.

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Matching PR in forked repository

PR in forked repository: lhotari#91

[Jason918]

LGTM