This PR adds support for the 'fields' option in the following places:
* Anytime `inner_hits` is used, for both fetching nested/ child docs and field collapsing
* The `top_hits` aggregation
Addresses #61949.
No-op changes to:
* Move `Search your data` source files into the same directory
* Rename `Search your data` source files based on page ID
* Remove unneeded includes
* Remove the `Request` dir