[Develop] Upgrade Linter System

[nathanlesage]

Starting with version 9, ESLint has completely removed the previous .eslintrc.json file format and instead switched to what they call a "flat" file format that at least on the outset doesn't feel very flat.

Anyhow, since the linters in VS Code and ESLint somehow seemed to have diverged over the years anyhow, I decided that it's a good idea to do a full revamp of the linter system to fix the following issues:

1. Differences in how VS Code/TSLint and ESLint (via yarn lint) interpret rules
2. What rules are even used? Should we change something (there are a ton of linter warnings still)?
3. Does the setup of using VS Code with TSLint and ESLint on the continuous integration pipeline even make sense?