Update error messages when supervisor's checkpoint state is invalid

[abhishekrb19]

Updating the topic name for a supervisor results in the following error:

[java.lang.RuntimeException: Inconsistent metadata state. This can happen if you update input topic in a spec without changing the supervisor name. Stored state: ...

Changing the supervisor's name makes it a completely different supervisor. Update the error message to instead suggest resetting the supervisor as the primary way to fix it when this happens. The updated error message is as follows:

org.apache.druid.error.DruidException: Inconsistency between stored metadata state[ObjectMetadata{theObject={foo=baz}}] and target state[ObjectMetadata{theObject=null}]. Try resetting the supervisor.

• Also, update the error message when the start metadata is ahead of the last committed state.

Other cleanup changes:

• Switch startMetadataGreaterThanExisting from an integer to boolean type to make the intent clear.
• Replace an anonymous code block with lambda.
• Use DruidException instead of RuntimeException in SegmentPublishResult failure calls.
• Clean up a few code comments, redundant info log and include more information in the SegmentPublishResult error itself.

This PR has:

• been self-reviewed.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.

[kfaraz]

Thanks!