fix(plugin-legacy): bake-in Promise polyfill, fix #4414

[AlexandreBonaventure]

Description

This fixes support for ie11 with legacy plugin.
see #4414 for the reasoning
This adds 2 polyfills per default, which can maybe improved by only injecting them when required (ie: only for ie11 and below) and not add to the bundle size for those that supports Promise

Additional context

---

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Before submitting the PR, please make sure you do the following

• Read the Contributing Guidelines.
• Read the Pull Request Guidelines and follow the Commit Convention.
• Check that there isn't already a PR that solves the problem the same way to avoid creating a duplicate.
• Provide a description in this PR that addresses what the PR is solving, or reference the issue that it solves (e.g. fixes #123).
• Ideally, include relevant tests that fail without this PR but pass with it.