[BUG] Pagination of index aliases is not supported

What is the bug?
Pagination of index alias does not work.

How can one reproduce the bug?
Steps to reproduce the behaviour:

1. Create an index -- indexA -- and load data
2. Create an alias -- aliasA -- for the index
3. Send query like SELECT * FROM aliasA with non-zero fetch_size
4. See error like

{
    "error": {
        "details": "Index type [alias_phrases] does not exist",
        "reason": "There was internal problem at backend",
        "type": "IllegalArgumentException"
    },
    "status": 500
}

What is the expected behavior?
Paging an index directly or its alias should produce the same result.

See this stack overflow question for reference.

Start by reproducing the non-zero fetch_size query against an index and its alias, then trace the pagination handling that produces the missing index type error. Done means paging the alias produces the same results as paging the index directly.