Changes NativeEngineKNNQuery to execute search and rescore in createWeight phase

[shatejas]

rewrite is executed in QueryPhase and FetchPhase in opensearch, this increases the query latency. As an alternative, the search logic is moved to createWeight phase. This will only be used when there is a rescore context present, as a result this will only execute when the mode is set to on-disk

Check List

• [x] New functionality includes testing.
• [x] Commits are signed per the DCO using --signoff.

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[opensearch-trigger-bot[bot]]

The backport to 2.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-2.x 2.x
# Navigate to the new working tree
cd .worktrees/backport-2.x
# Create a new branch
git switch --create backport/backport-2014-to-2.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 9dbe7de078616da9d95c27883c468c4ef4b7df4a
# Push it to GitHub
git push --set-upstream origin backport/backport-2014-to-2.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-2.x

Then, create a pull request where the base branch is 2.x and the compare/head branch is backport/backport-2014-to-2.x.

[naveentatikonda]

@shatejas backport to 2.x failed. Can you fix it and raise a PR. Thanks!