Remove isSingleRequest true from codebase

What does this MR do and why?

2nd MR as mentioned in Remove FF unbatch_graphql_queries (!132433 - merged)

This MR handles removal of isSingleRequest from the codebase after the FF unbatch_graphql_queries was defaulted to on as per this comment.

This is just a clean up and all the original work is done by @ntepluhina 🙏 She was gracious to trust me with the cleanup 🙇

Screenshots or screen recordings

N/A

How to set up and validate locally

1. Go to any page and verify that the graphql queries are unbatched
2. See that all the pages that have the flag removed work as expected

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.