### Description

`stats x = count`  throws error `unknown column [count]` which is confusing since stats does not allow aliasing for existing columns but only points to aggregate functions.
Hence why the message should be `incorrect function declaration count, you forgot to add the parantheisis`. 
Same approach when dealing with a typo: `stats x = cont(*)` - `Unkown aggregate function cont - did you mean count()?`

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/analysis/VerifierTests.java
return error(query, defaultAnalyzer);
    }
    private String error(String query, Object... params) {
        return error(query, defaultAnalyzer, params);
    }
    private String error(String query, Analyzer analyzer, Object... params) {
        List<TypedParamValue> parameters = new ArrayList<>();
        for (Object param : params) {
            if (param == null) {
                parameters.add(new TypedParamValue("null", null));
            } else if (param instanceof String) {
                parameters.add(new TypedParamValue("keyword", param));
            } else if (param instanceof Number) {
                parameters.add(new TypedParamValue("param", param));
            } else {
                throw new IllegalArgumentException("VerifierTests don't support params of type " + param.getClass());
            }
        }
        VerificationException e = expectThrows(
            VerificationException.class,
            () -> analyzer.analyze(parser.createStatement(query, parameters))
        );
        String message = e.getMessage();
        assertTrue(message.startsWith("Found "));
        String pattern = "\nline ";
        int index = message.indexOf(pattern);
        return message.substring(index + pattern.length());
    }
}