ResourceLoaderImage: Correctly ignore 'deprecated' key
It turns out that 'resources/lib/oojs-ui/themes/mediawiki/Moved since v0.20.1, use from the 'interactions' pack instead.'
is not usually an existing file, and doesn't have the extension '.svg'.
Not sure why this didn't break earlier.
Bonus: Add module name to exceptions to make these errors easier
to track down.
Bonus #2: Use the post-expansion, not pre-expansion, definition everywhere
to avoid confusion when debugging.
Change-Id: I0325d4dab5658fd29c3c33fd3e762834b53d1b5d