Add a function to aggregate a string attribute of events in a stream and concatenate to a single string

[this]

Description:
Add a function that aggregate a specified string attribute of events in a stream and concatenate to them into a single string. This function should behave similar to MySQL GROUP_CONCAT function.

SELECT student_name,
GROUP_CONCAT(test_score)
FROM student
GROUP BY student_name;

Affected Product Version:
Siddhi v4.x.x