Rework jest configuration, move jest and babel configs to scripts, remove extraneous files

[JasonVMo]

Platforms Impacted

• all / but testing only

Description of changes

This reworks the jest configuration and moves them into scripts so we don't have a ton of extraneous packages floating about. Some notes:

• the react / rn-platform versions switch on furn.jestPlatform in package.json files
• the babel config is set up directly, rather than requiring a babel.config.js file in each folder
• the configs are now jest.config.cjs. This avoids having to change from require to import every time we switch a package to esm.
• removed old packages that are no longer needed
• removed tool focused capabilities as everything will eventually be in scripts

Verification

Tests pass