title: Are there any contexts when specified WebView panel is active in VSCode extension keybinding contribution points?
body: <p>I saw the <a href="https://code.visualstudio.com/docs/getstarted/keybindings#_when-clause-contexts" rel="nofollow noreferrer">when-clause-contexts</a> document but I can't find something like that... Is there any conditions WebView panel is active or alternatives?</p>
  
  <p>I'm now making copy &amp; paste feature in my extension but if <code>when</code> is not specified, some default keybindings may be blocked.</p>