feat(query): add feature flag list-in-normalize

[mangalaman93]

This feature flag allows configuring @normalize in the query language such that if there are multiple fields with same alias, they could be returned as a list or non-list.

There was a breaking change at some point with the PR #7639. Some customers do not prefer a list response in case of @normalize. We would like to not make any breaking changes going forward, and hence, introducing this feature flag enables users to make that choice.

[joshua-goldstein]

Which future release is this going into, since this is a breaking change? Will we bring this into v23?

[MichelDiz]

Just a question, are you sure about this?
I remember this behavior being a request from the community. I don't record exactly, but there was a discussion about this back then. Do we have a new discussion to revert this?
The previous behavior in my opinion is invalid even by JSON standards. Where two keys cannot have the same name in the same object.

e.g from the PR:

"b2": [
      {
        "Name": "Process",
        "id": "Process",
        "Name":"Namespace",
        "id": "Core/Namespace"
      }
    ]

"b2": [
      {
        "Name": [
          "Process",
          "Namespace"
        ],
        "id": [
          "Process",
          "Core/Namespace"
        ]
      }
]

[mangalaman93]

Modified the PR to provide a feature flag which is enabled by default. It can be disabled if needed.