Fix Type1 font parsing when .notdef is not at index zero

Fixes #11477
The PDF draws many space characters but the embedded fonts don't have a glyph named `space`, so `.notdef` should be drawn instead. PDF.js assumed that Type1 fonts define `.notdef` as the first glyph (index 0). However, now the fonts have the glyph `A` at index 0 and `.notdef` is the last one, so `A` appears where spaces are expected.

Because the rest of the font machinery in `core/fonts.js` assumes `.notdef` is at index zero, it's easiest to modify `core/type1_parser.js` so that it "repairs" fonts and makes sure `.notdef` is at index 0.

test/pdfs/.gitignore

@@ -299,6 +299,7 @@
 !issue4573.pdf
 !issue4722.pdf
 !issue4800.pdf
+!issue11477_reduced.pdf
 !text_clip_cff_cid.pdf
 !issue4801.pdf
 !issue5334.pdf

test/test_manifest.json

@@ -1456,6 +1456,12 @@
        "rounds": 1,
        "type": "eq"
     },
+    {  "id": "issue11477",
+       "file": "pdfs/issue11477_reduced.pdf",
+       "md5": "f4e5735569afce79e52b3fd56d10ae13",
+       "rounds": 1,
+       "type": "eq"
+    },
     {  "id": "issue7665",
        "file": "pdfs/issue7665.pdf",
        "md5": "f1199d16195a61e8232e2d1e742ed46b",