### 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/main/java/org/elasticsearch/xpack/esql/analysis/Verifier.java
*
     * @param plan The logical plan to be verified
     * @return a collection of verification failures; empty if and only if the plan is valid
     */
    Collection<Failure> verify(LogicalPlan plan) {
        Set<Failure> failures = new LinkedHashSet<>();
        
        plan.forEachUp(p -> {
            
            if (p.childrenResolved() == false) {
                return;
            }
            if (p instanceof Unresolvable u) {
                failures.add(fail(p, u.unresolvedMessage()));
            }
            
            else if (p.resolved()) {
                return;
            }
            p.forEachExpression(e -> {
                
                if (e.resolved()) {
                    return;
                }
                e.forEachUp(ae -> {
                    
                    if (ae.childrenResolved() == false) {
                        return;
                    }
                    if (ae instanceof Unresolvable u) {