Use esm syntax for replay defaults and related maintenance

[matux]

Description of the change

Description by Copilot.

This pull request refactors the module export structure across several files to adopt ES module syntax (export/import) instead of CommonJS (module.exports). The changes improve consistency, readability, and alignment with modern JavaScript standards.

Refactoring to ES module syntax:

• src/browser/replay/defaults.js: Replaced module.exports with export default for the default options object.
• test/fixtures/replay/rrwebEvents.fixtures.js: Converted rrwebEvents from a CommonJS export to an ES module export using export const. Removed the redundant export { rrwebEvents }; statement. [1] [2]
• test/fixtures/replay/rrwebSyntheticEvents.fixtures.js: Updated syntheticEvents to use export const and removed the redundant export { syntheticEvents }; statement. [1] [2]
• test/fixtures/replay/types.js: Removed the module.exports block entirely, as individual exports (export const) are already defined for each type.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

• CAT-353/rrweb-integration

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

[Copilot]

Pull Request Overview

This PR refactors several files to adopt ES module syntax from CommonJS, improving consistency and modernizing the codebase. Key changes include:

• Converting default exports in the browser defaults file to ES module exports.
• Rewriting fixture files to use named exports and removing redundant export statements.
• Removing the CommonJS module.exports block in the types definitions file.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
src/browser/replay/defaults.js	Converted module.exports to export default for the default options object.
test/fixtures/replay/rrwebSyntheticEvents.fixtures.js	Changed syntheticEvents to export const and removed redundant export statement.
test/fixtures/replay/rrwebEvents.fixtures.js	Changed rrwebEvents to export const and removed redundant export statement.
test/fixtures/replay/types.js	Removed the module.exports block in favor of individual exports.