title: Kusto KQL equivalent to string_agg in mysql
body: <p>Is there a way to concatenate a column in Kusto KQL?</p>
  
  <p>For example, for some <code>world</code> dataset with a column <code>name</code> in MySQL (v8):</p>
  
  <pre class="lang-sql prettyprint-override"><code>select group_agg(name) from world;
  </code></pre>
  
  <p>would result in:</p>
  
  <pre><code>| string_agg                                    |
  |-----------------------------------------------|
  | Afghanistan,Azerbaijan,Bahrain,Bangladesh,... |
  </code></pre>