Originally reported here: https://github.com/firefox-devtools/debugger/issues/7208

When the debugger is paused, we show the Call stack panel.
On this panel we have a list of all the frames of the stack.
On each frame, the user can right-click to get a context menu offering frame related actions:

<img width="301" alt="image" src="https://user-images.githubusercontent.com/578107/47779178-c763b280-dcf8-11e8-8fe3-147767709726.png">

Except some actions are not really strictly-related frame action:

• Copy stack trace is about the whole component
• Disable framework grouping is also about the stacktrace. What's even more confusing is that "group frames" don't have the onContextMenu handler, so you can't disable framework grouping by right-clicking on a group.

I think it would be nice to only have in this menu the Frame related actions.
Copy stacktrace and toggle framework grouping could be moved into the call stack header:

+---------------------------------+
| ▼ Call stack                  ⚙︎ |
+---------------------------------+
| render                App.js:22 |
| finishClassComponent      React |
+---------------------------------+

Clicking on the gear icon would open a new menu with the 2 actions.

Or, we could have 2 different icons for those actions directly in the header

+---------------------------------+
| ▼ Call stack              🖋 🔗 |
+---------------------------------+
| render                App.js:22 |
| finishClassComponent      React |
+---------------------------------+

(even though those icons could be tricky to get right)