[Improvement]: Confusing error message when collect sum is used with non sequence reference

[manuranga]

Description

import ballerina/io;

public function main() {
    string s = "12manu245xyz";
    int numbersCount = from var m in s
        let int code = m.getCodePoint(0)
        where code >= 48 && code <= 57
        collect sum(1);
    io:println(numbersCount);
}

Above code gives undefined function 'sum' error.

Describe your problem(s)

This error is confusing, since sum function is available and works if I put code in sum.

Describe your solution(s)

It should give something like non-sequence reference not not supported in collect clause error.

[manuranga]

Moved to #42036