Use ESLint to ensure that exports are sorted alphabetically

There's built-in ESLint rule, see `sort-imports`, to ensure that all `import`-statements are sorted alphabetically, since that often helps with readability.
Unfortunately there's no corresponding rule to sort `export`-statements alphabetically, however there's an ESLint plugin which does this; please see https://www.npmjs.com/package/eslint-plugin-sort-exports

The only downside here is that it's not automatically fixable, but the re-ordering is a one-time "cost" and the plugin will help maintain a *consistent* ordering of `export`-statements in the future.
*Note:* To reduce the possibility of introducing any errors here, the re-ordering was done by simply selecting the relevant lines and then using the built-in sort-functionality of my editor.

src/core/core_utils.js

@@ -323,17 +323,17 @@ function collectActions(xref, dict, eventType) {
 export {
   collectActions,
   escapePDFName,
-  getLookupTableFactory,
   getArrayLookupTableFactory,
-  MissingDataException,
-  XRefEntryException,
-  XRefParseException,
   getInheritableProperty,
-  toRomanNumerals,
+  getLookupTableFactory,
+  isWhiteSpace,
   log2,
+  MissingDataException,
   parseXFAPath,
   readInt8,
   readUint16,
   readUint32,
-  isWhiteSpace,
+  toRomanNumerals,
+  XRefEntryException,
+  XRefParseException,
 };