Merge four front-end Github repositories into one

## What is the problem?
At present, our single-page application is split across four Github repositories. Apparently, when the project was initially setup, the application was split into multiple repos to avoid merge conflicts and to allow for different architectures.

## What is the impact?
There is a significant amount of code duplication across repos. It's difficult and time consuming to share code across repos, so developer effort is being wasted. Developers have to remember subtle differences in the application scaffolding which makes troubleshooting and on-boarding new team members more challenging.

## Proposed solution
This is a major undertaking but has significant benefits. Pick a repo to become the eventual repository of all front-end code -- filings-ui would make a logical choice. Clean up the App.vue files in each repo. Having a clean, minimalist App.vue makes it easier to move routes from one repo to another and allows the application to support multiple architectures.