Increase the computed value of replicationThrottleLimit

[kfaraz]

Description

In the smartSegmentLoading mode, the Coordinator is able to handle unlimited load queues.

So, it is safe to increase the computed values of replicationThrottleLimit to allow segments to reach max replication levels faster.

It is possible to even completely remove the replicationThrottleLimit but we would want to retain it to prevent unnecessary loads on servers in case a server disappears from the cluster intermittently.

Changes

• Increase value of replicationThrottleLimit computed by smartSegmentLoading from 2% to 5% of total number of used segments.
• Assign replicas to a tier even when some replicas are already being loaded in that tier
• Limit the total number of replicas in load queue at start of run + replica assignments in the run to the replicationThrottleLimit.

for every tier,
    num replicas in load queue at start of run + num replicas assigned in run <= replicationThrottleLimit

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This PR has:

• been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.

[AmatyaAvadhanula]

LGTM! +1 after all the checks pass

[kfaraz]

Thanks for the review, @AmatyaAvadhanula !