title: Robot Framework HTML format for several MESSAGE in report
body: <p>I would like to define the * HTML * format of the "message" field in the robotframework report</p>
  
  <p>For example: If I have a 1st error message defined with the message field of the Keyword 'Page should contains element'
  The 2nd message will be defined in 'Set Test Message'</p>
  
  <p>Code example:</p>
  
  <pre><code>Page should contains element | locator | message=Error message1
  </code></pre>
  
  <p>Another Keyword</p>
  
  <pre><code>Set test message | * HTML * &lt;b&gt;Error message2&lt;/b&gt; | append=True
  </code></pre>
  
  <p>In report message block i have :    </p>
  
  <pre><code>Error message1 &lt; b &gt;Error message2&lt; /b &gt;
  </code></pre>
  
  <p>If i set <code>* HTML *</code> in message= <code>* HTML *Error message1</code> i can see <code>* HTML *</code> label in report</p>
  
  <p>I would like define <code>${TEST MESSAGE}=* HTML * + ${TEST MESSAGE}</code></p>