### 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
error("from test | rename emp_no as r1, emp_no as r1 | keep r1")
        );
    }
    public void testDoubleRenamingReference() {
        assertEquals(
            "1:61: Column [r1] renamed to [r2] and is no longer available [r1 as r3]",
            error("from test | rename emp_no as r1, r1 as r2, first_name as x, r1 as r3 | keep r3")
        );
    }
    public void testDropAfterRenaming() {
        assertEquals("1:40: Unknown column [emp_no]", error("from test | rename emp_no as r1 | drop emp_no"));
    }
    public void testNonStringFieldsInDissect() {
        assertEquals(
            "1:21: Dissect only supports KEYWORD or TEXT values, found expression [emp_no] type [INTEGER]",
            error("from test | dissect emp_no \"%{foo}\"")
        );
    }
    public void testNonStringFieldsInGrok() {
        assertEquals(
            "1:18: Grok only supports KEYWORD or TEXT values, found expression [emp_no] type [INTEGER]",
            error("from test | grok emp_no \"%{WORD:foo}\"")
        );
    }
    public void testMixedNonConvertibleTypesInIn() {
        assertEquals(
            "1:19: 2nd argument of [emp_no in (1, \"two\")] must be [integer], found value [\"two\"] type [keyword]",
            error("from test | where emp_no in (1, \"two\")")
        );
    }