Standardize MFEs to reduce total complexity

[jmakowski1123]

Problem

Instead of one complex monolith, we now have several less-complex projects in addition to the big one we started with. Plus, while less complex individually, MFEs are collectively harder to work with.

Product/Platform Value

Reducing the cost of onboarding is also an important aspect of fostering adoption: the easier it is for providers to train their developers, the more use-cases the platform can be used for.

Acceptance Criteria

Standardize MFEs as much as possible, so that a good part of developer and deployment complexities can be learned once and reused across repositories, all while avoiding freezing the technology in time (which is what happened with edx-platform).

Related or in-progress work

Contingencies

This should be scoped in parallel with the epic to finish the MFE conversion process.

[arbrandes]

Closing in favor of #437.