Add "Copy qualifier '...' value" item to the main menu

Scenario:

1. Open an annotated sequence (e.g. "murine.gb").
2. Select a qualifier in the Annotations Editor (e.g. "product" qualifier for the first "CDS" annotation).
3. Right-click on the qualifier.
   Expected result: there is item "Copy/Paste > Copy qualifier 'product' value".
4. Select the item.
   Expected result: the value of the qualifier is in the clipboard (e.g. "enhanced green fluorescent protein").
5. Open "Actions > Copy/Paste" in the main UGENE menu.
   Expected result: there is "Copy qualifier 'product' value" item.
   Current result: there is no such item in the main menu.

See also: http://ugene.net/forum/YaBB.pl?num=1531453404/0#8.