### Description

This is to investigate what we could do to support the data streams in SQL. The backing indices can be queried already, but to address them similarly as they're queried over QDSL one would need to construct a pattern learned out of band and not through SQL metadata discovery mechanisms.
x-pack/plugin/sql/qa/server/src/main/java/org/elasticsearch/xpack/sql/qa/rest/BaseRestSqlTestCase.java
private static final String TEST_INDEX = "test";
    public static class RequestObjectBuilder {
        private StringBuilder request;
        private final boolean isQuery;
        private RequestObjectBuilder(String init, boolean isQuery) {
            request = new StringBuilder(init);
            this.isQuery = isQuery;
        }
        public static RequestObjectBuilder query(String query) {
            return new RequestObjectBuilder(field(QUERY_NAME, query).substring(1), true);
        }
        public static RequestObjectBuilder cursor(String cursor) {
            return new RequestObjectBuilder(field(CURSOR_NAME, cursor).substring(1), false);
        }
        public RequestObjectBuilder version(String version) {
            request.append(field(VERSION_NAME, version));
            return this;
        }
        public RequestObjectBuilder mode(Object m) {
            String modeString = m.toString();
            request.append(field(MODE_NAME, modeString));
            if (isQuery) {
                Mode mode = (m instanceof Mode) ? (Mode) m : Mode.fromString(modeString);
                if (Mode.isDedicatedClient(mode)) {
                    version(Version.CURRENT.toString());
                }
            }
            return this;
        }
        public RequestObjectBuilder fetchSize(Integer fetchSize) {