@grafana/e2e: fix empty bundle files (#22607)

* Minor changes

* Revert CLI to JavaScript

... as Rollup is only accepts ESM modules and TypeScript would need to use the new incremental builds feature which causes weird Redux module errors.

packages/grafana-e2e/cli.js

@@ -0,0 +1,39 @@
+const execa = require('execa');
+const program = require('commander');
+const { resolve, sep } = require('path');
+
+const cypress = commandName => {
+  // Support running an unpublished dev build
+  const dirname = __dirname.split(sep).pop();
+  const projectPath = resolve(`${__dirname}${dirname === 'dist' ? '/..' : ''}`);
+
+  const cypressOptions = [commandName, '--env', `CWD=${process.cwd()}`, `--project=${projectPath}`];
+
+  const execaOptions = {
+    cwd: __dirname,
+    stdio: 'inherit',
+  };
+
+  return execa(`${projectPath}/node_modules/.bin/cypress`, cypressOptions, execaOptions)
+    .then(() => {}) // no return value
+    .catch(error => console.error(error.message));
+};
+
+module.exports = () => {
+  const configOption = '-c, --config <path>';
+  const configDescription = 'path to JSON file where configuration values are set; defaults to "cypress.json"';
+
+  program
+    .command('open')
+    .description('runs tests within the interactive GUI')
+    .option(configOption, configDescription)
+    .action(() => cypress('open'));
+
+  program
+    .command('run')
+    .description('runs tests from the CLI without the GUI')
+    .option(configOption, configDescription)
+    .action(() => cypress('run'));
+
+  program.parse(process.argv);
+};