title: PrimeNG table filtering and sorting on each column doesn't work
body: <p>I'm creating a table using PrimeNG.
  I want to allow the user to sort AND filter by column.
  I can successfully sort, but when I try to type in the filter text input of any column, the input loses focus and the column gets sorted.
  I've debugged a little and it seems like the sorting functionality of primeNG is activated whenever a click is captured in the header of the table. Since my filter input is inside the header, when I try to click on it to start typing, it activates the sort and I lose focus.</p>
  
  <p>Stackblitz reproduction: <a href="https://stackblitz.com/edit/primeng-table-g9uxkf" rel="nofollow noreferrer">https://stackblitz.com/edit/primeng-table-g9uxkf</a></p>
  
  <p>Any idea on how I could counter this?</p>
  
  <p>Thank you in advance.</p>