Remove several unnecessary layers of indirection from refs

[josephcsible]

No description provided.

[jgm]

This looks right to me. Have you tested it on a real-world case that would exercise this code, just to make sure?

[josephcsible]

It passes both the zotero with +citations and mendeley with +citations unit tests. To confirm those exercise this code, I tried with this intentionally-wrong change:

diff --git a/src/Text/Pandoc/Readers/Docx.hs b/src/Text/Pandoc/Readers/Docx.hs
index 7abbc461d..12106b2ea 100644
--- a/src/Text/Pandoc/Readers/Docx.hs
+++ b/src/Text/Pandoc/Readers/Docx.hs
@@ -551,7 +551,7 @@ handleCitation citation = do
                                         -- see #10366, sometimes itemData has a different
                                         -- id and we need to use the same one:
                                         itemData{ referenceId =
-                                                    Citeproc.citationItemId item })
+                                                    ItemId "wrong" })
                                   (Citeproc.citationItemData item)) items
   modify $ \st ->
     st{ docxReferences = foldr

And that made both of them fail.