Make `redux` and `react-redux` optional peer dependencies

[adamstankiewicz]

Currently, frontend-platform requires MFEs to install redux and react-redux even if the MFE doesn't use Redux. frontend-platform renders an OptionalReduxProvider component, where if no store prop is passed to <AppProvider> within the MFE, Redux's Provider is not rendered.

However, for MFEs that opt to NOT use Redux (e.g., frontend-app-learner-portal-enterprise), these peer dependencies are still required to install, even though they're not used.

Ideally, frontend-platform could denote these peer dependencies as being optional, handling it accordingly when the package is not installed.

[adamstankiewicz]

See #763, which includes a fix for this issue.

Note it uses the following:

{
  "peerDependenciesMeta": {
    "redux": {
      "optional": true
    },
    "react-redux": {
      "optional": true
    }
  }
}

instead of optionalDependencies, which corresponds to how many common React libraries handle optional peer dependencies.

[adamstankiewicz]

The changes in #763 ended up breaking tests on consuming MFEs due to the async lazy import of Provider from react-redux in OptionalReduxProvider.

Next steps:

• Reintroduce the changes to make redux and react-redux truly optional from the above PR.
  • Ideally, see if it can be done in a non-breaking way (e.g., does it make sense to move the lazy inside OptionalReduxProvider vs. externally to the component, such that the suspended component only impacts tests when rendered?
  • If it must be a breaking change, ensure it is released as such.

[adamstankiewicz]

[inform] Opened a new standalone PR for this contribution: #768