Add "Copy Test ID" option to gutter icon context menu

[MetRonnie]

It would be really convenient if the "Copy Test ID" option (added in #25257) were to be also added to the right click context menu for the test buttons in the editor gutter (see red circle):

[connor4312]

The original feature request is asking to

have it be in the pytest format: path/to/module.py::Class::function

This isn't something we have on the vscode core side, so I think it would be a Python extension thing for the testing/item/gutter menu.