Add the caniuse-lite package

Since the Autoprefixer plugin indirectly depends on this, it seems like a good idea to add this as a direct dependency in the PDF.js project to hopefully avoid having to manually update `caniuse-lite` in the future; see https://github.com/browserslist/browserslist#browsers-data-updating

Also, slightly tweaks the Autoprefixer config for GENERIC-builds of the PDF.js library; note that this change doesn't affect the contents of the *built* `web/viewer.js` file.

Author: Snuffleupagus

gulpfile.js

@@ -81,7 +81,7 @@ const AUTOPREFIXER_CONFIG = {
     "Chrome >= 73",
     "Firefox ESR",
     "Safari >= 12.1",
-    "> 0.5%",
+    "> 1%",
     "not IE > 0",
     "not dead",
   ],

package-lock.json

@@ -10,6 +10,7 @@
     "acorn": "^8.7.0",
     "autoprefixer": "^10.4.2",
     "babel-loader": "^8.2.3",
+    "caniuse-lite": "^1.0.30001312",
     "canvas": "^2.9.0",
     "core-js": "^3.21.1",
     "cross-env": "^7.0.3",