Fix webservice copy-to menu items

[tchx84]

Retrieve metadata when populating the copy-to menu items
for webservices.

Pass metadata instead of the callback reference, to preserve
compatibility with current extensions.

Signed-off-by: Martin Abente Lahaye tch@sugarlabs.org

[tchx84]

@walterbender can you test it? :)

[godiard]

I think is better modify the webservices.
Why? The palette is created every time, the user press the secondary button,
or is triggered by the time out, and you need do a query to the journal.
Is better do it only in the case the user decide use the webservice.

[walterbender]

Ironically, that is how we first implemented the change :) Easy enough.

[tchx84]

I can revert this change. But, to take @godiard comment into account it will require to modify the webservices code (not only extensions) to actually use the callback in a on-demand manner.

@walterbender, @godiard What do you guys think? Should I proceed? :)