Remove unused dependencies, misc. small fixes

[trgwii]

• Remove dotenv in favor of --env-file-if-exists=.env (v22.9.0). We can switch to --env-file=.env (v20.6.0), but it will fail to start if .env is missing, or we can restore dotenv for now.
• Remove cross-env (used only for NODE_ENV=production|development) in favor of a CLI argument --production which is checked in server/env.js and sets process.env.NODE_ENV to production or development if it was not already set.
• Switch sqlite3 to better-sqlite3, most of the deprecation warnings come from sqlite3, so here's a before / after:

  # before:
  npm warn deprecated [email protected]: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.
  npm warn deprecated @npmcli/[email protected]: This functionality has been moved to @npmcli/fs
  npm warn deprecated [email protected]: Rimraf versions prior to v4 are no longer supported
  npm warn deprecated [email protected]: This package is no longer supported.
  npm warn deprecated [email protected]: Rimraf versions prior to v4 are no longer supported
  npm warn deprecated [email protected]: Rimraf versions prior to v4 are no longer supported
  npm warn deprecated [email protected]: Rimraf versions prior to v4 are no longer supported
  npm warn deprecated [email protected]: This package is no longer supported.
  npm warn deprecated [email protected]: Glob versions prior to v9 are no longer supported
  npm warn deprecated [email protected]: node-mailer is not maintained
  npm warn deprecated [email protected]: This package is no longer supported.
  
  # after:
  npm warn deprecated [email protected]: This module is not supported, and leaks memory. Do not use it. Check out lru-cache if you want a good and   tested way to coalesce async requests by a key value, which is much more comprehensive and powerful.
  npm warn deprecated [email protected]: Rimraf versions prior to v4 are no longer supported
  npm warn deprecated [email protected]: Glob versions prior to v9 are no longer supported

  (The remaining deprecation warnings all come from geoip-lite).

• Replaced node-cron with setInterval, it was only being used to call a function every 30 seconds in server/cron.js.
• Removed node-mailer (unused). nodemailer is used and remains.
• Replace uuid (only v4 is used) with builtin crypto.randomUUID() (v14.17.0).
• Require all builtin modules using node: prefix. (support added in v14.18.0)
• Standardize to double quotes everywhere (No linting / autoformatting added).
• Remove some unused imports.

[poeti8]

Changing the base to the develop branch since I'd want to test the published Docker image for development before merging into main

[poeti8]

Got closed accidentally XD

Pushed your commit to develop now, I'll merge into main from there.

Oh by the way, I added back dotenv, --env-file-if-exists=.env is quite new, can't afford to tell everyone to use the latest version of Node.js