Convert to monorepo, add remote eval

[bryce-fitzsimons]

Convert to monorepo, add remote evaluation support:

• Separate out the proxy app to its own package
• Create a new remote evaluation package
• Publish all packages independently to NPM
• Fix several security vulnerabilities
• Require Node 18+
• Bump proxy's minor version number

[jdorn]

This is sending the full experiment object down, including variations that were not assigned. Do we want to do the same filtering we're doing below to remove that info?

[bryce-fitzsimons]

added filtering