Migrate off babel-plugin-react-intl in favor of babel-plugin-formatjs

[adamstankiewicz]

The babel-plugin-react-intl package that @edx/frontend-build uses in its Babel configs is deprecated in favor of babel-plugin-formatjs.

AC

• Modify @edx/frontend-build to no longer rely on babel-plugin-react-intl in favor of babel-plugin-formatjs.

PRs

• refactor: migrated off babel-plugin-react-intl frontend-build#258

[arbrandes]

@BilalQamar95, just checking: are you working on this? Or should we put it in the backlog for somebody else to pick up?

[BilalQamar95]

@arbrandes There is a PR for it waiting for review

[arbrandes]

PR was reviewed, but there are some remaining concerns. In other words, this is still in progress.

[arbrandes]

Looks like we're done here. Thanks for all this work!