CNDB-15469: Add NVQunatization::create method that takes global mean

[michaeljmarshall]

In some applications, it will be better to compute the global mean iteratively at the time of insertion into the graph instead of when creating the NVQuantization object. Therefore, I propose adding a new create method that takes an already computed scaled global mean vector.

Because we update the existing compute method to call this new create method, the existing tests fully cover the new method.

This work is part of https://github.com/riptano/cndb/issues/15469.

[github-actions]

Before you submit for review:

• Does your PR follow guidelines from CONTRIBUTIONS.md?
• Did you summarize what this PR does clearly and concisely?
• Did you include performance data for changes which may be performance impacting?
• Did you include useful docs for any user-facing changes or features?
• Did you include useful javadocs for developer oriented changes, explaining new concepts or key changes?
• Did you trigger and review regression testing results against the base branch via Run Bench Main?
• Did you adhere to the code formatting guidelines (TBD)
• Did you group your changes for easy review, providing meaningful descriptions for each commit?
• Did you ensure that all files contain the correct copyright header?

If you did not complete any of these, then please explain below.