ayesha-ilm has created PR #2606: GODRIVER-3954: Implement ServerErrorInterface for ClientBulkWriteException in mongo-go-driver

Issue Text:
GODRIVER-3954(https://jira.mongodb.org/browse/GODRIVER-3954)

1. 1. Summary

<!--- A summary of the changes proposed by this pull request. -->

ClientBulkWriteException now implements the full ServerError interface.

1. 1. Background & Motivation

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ClientBulkWriteException did not implement the full ServerError interface. As a result, errors.As(err, &serverErr) returns false for a client bulk write error, and the idiomatic server-error detection path.

1. 1. What I have done

added missing interface functions:

• HasErrorLabel
• HasErrorMessage
• HasErrorCodeWithMessage

to ClientBulkWriteException

1. 1. Test Plans