Grid model's context menu copy items do not work on iPad when certain custom menu items are present

[saba-mo]

The three copy items in Grid Model's default context menu sometimes do not work on iPad when there are custom menu items preceding them. The client reported it appeared you could copy but then nothing would paste. Removing the custom items fixed the issue.

This is only apparent on an actual device - nothing is broken on emulator. It also appears to only be an issue on the client's mobile browser; it was not an issue when testing toolbox directly on the iPad - hoist's admin log viewer grid was tested.

More testing is needed, as there are examples of custom context menus that are working correctly while others are broken.