Build: Add `exports` to package.json, export slim & esm builds

Summary of the changes:
* define the `exports` field in `package.json`; `jQuery` & `$` are also
  exported as named exports in ESM builds now
* declare `"type": "module"` globally except for the `build` folder
* add the `--esm` option to `grunt custom`, generating jQuery as an ECMAScript
  module into the `dist-module` folder
* expand `node_smoke_tests` to test the slim & ESM builds and their various
  combinations; also, test both jQuery loaded via a path to the file as well
  as from module specifiers that should be parsed via the `exports` feature
* add details about ESM usage to the release package README
* run `compare_size` on all built minified files; don't run it anymore on
  unminified files where they don't provide lots of value
* remove the remove_map_comment task; SWC doesn't insert the
`//# sourceMappingURL=` pragma by default so there's nothing to strip

Fixes gh-4592
Closes gh-5255

1 files changed, 2 insertions, 2 deletions

diff --git a/build/tasks/promises_aplus_tests.js b/build/tasks/promises_aplus_tests.js
index cb1a4fddb..1bbeff08e 100644
--- a/build/tasks/promises_aplus_tests.js
+++ b/build/tasks/promises_aplus_tests.js
@@ -10,7 +10,7 @@ module.exports = grunt => {
 	grunt.registerTask( "promises_aplus_tests:deferred", function() {
 		spawnTest( this.async(),
 			"\"" + __dirname + "/../../node_modules/.bin/promises-aplus-tests\"" +
-				" test/promises_aplus_adapters/deferred.js" +
+				" test/promises_aplus_adapters/deferred.cjs" +
 				" --reporter dot" +
 				" --timeout " + timeout
 		);
@@ -19,7 +19,7 @@ module.exports = grunt => {
 	grunt.registerTask( "promises_aplus_tests:when", function() {
 		spawnTest( this.async(),
 			"\"" + __dirname + "/../../node_modules/.bin/promises-aplus-tests\"" +
-				" test/promises_aplus_adapters/when.js" +
+				" test/promises_aplus_adapters/when.cjs" +
 				" --reporter dot" +
 				" --timeout " + timeout
 		);