Added plural values to the clothing of Link, Shego, and Streaming-chan

To support forthcoming line functionality that can assess whether an item of clothing sounds plural, each character will need to be updated with a `plural=true` on selected lines in their wardrobe list. This is supported by the latest versions of the Character Editor (from v2.1.1) and make_xml (from v1.55).

I am going through and updating the xml files of characters who have had no content edits in the past six months. If you see the name of character you're working on, watch out for edit conflicts.

Link, Shego, and Streaming-chan were all last updated with version 1.13 of the Character Editor and have these minor changes in their diffs:

Link: one line had a custom priority that wasn't working; CE v2.1.1 wants to cut his one bolded line, but I did not commit that change
Shego: a targeted line to Zoey changed weight, so is now sorted correctly
Streaming-chan: no other changes