Move shared utility functions to frontend-platform for reuse across MFEs

[peterkulko]

Description

Currently, we have a set of useful utility functions being used in both the Learner Dashboard MFE and the Catalog MFE. It would be good to consider moving these functions into the frontend-platform repository so they can be reused across MFEs.

Note

At the time of creating this issue, the example usage of these functions in frontend-app-catalog is located in the RaccoonGang fork of the repository, but this code will be merged into the upstream repository’s master branch.

[arbrandes]

You mean resolveUrl and baseAppUrl?

I don't think I can object, but I am a little sad that we need these functions in the first place. For what it's worth, though, I don't think we'll need them in in frontend-base land.