title: Set log level for built in keywords in robotframework
body: <p>In robot framework, it looks like it logs messages for keywords like "=" by default with 'INFO' log level. Ex:</p>
  
  <pre><code>&lt;Test case&gt;
    ${xyz} = "hello"
  </code></pre>
  
  <p>Would log message with:</p>
  
  <pre><code>'INFO': ${xyz} = "hello"
  </code></pre>
  
  <p>I would like to lower the log level for this to 'DEBUG' or 'TRACE' but can't seem to find it in the source code.
  An advice for this?</p>