title: Removing all invalid characters (e.g. \uf0b7) from text
body: <p>I currently have several text coming in which sometimes contains the character 'invalid character' e.g. \uf0b7 or \uf077. I don't have a way of knowing which of the invalid character codes a specific text might contain and I wondered if there was a way to make sure that a string is cleaned of all types of 'invalid character', since a process later on (which is dependent on a third party package) can not receive a string which contains it.</p>
  
  <p>I've tried searching for a solution, but all I get it is answers regarding regular characters which people want removed (e.g. '^%$&amp;*') which they have classified as invalid characters, however I want to remove/replace the actual character 'invalid character' in all its forms</p>