Add a feature flag around the code with poor performance

What does this MR do and why?

Contributes to Performance problem with new projects page (#425166 - closed)

Problem

!130933 (merged) has introduced a performance problem.

Solution

Mitigate the problem by adding a feature flag around new code in disabled state. That will allow us to investigate the problem without affecting customers.

Screenshots or screen recordings

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

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