Lint rules and code patterns for typescript node code

[zepumph]

Since adding typescript node JS code in https://github.com/phetsims/chipper/issues/1437, I think there may be good questions to answer about how our linting system or code style may want to differ. We started parsing this with some rule changes here:

https://github.com/phetsims/chipper/blob/93d830f215be91c9ed094f40ae785cccdfa4a48e/eslint/node.eslint.config.mjs#L13-L29

But there is still more to do, and I don't want these questions to block pattern making/propagation or converting files to TypeScript. Let's keep them here!

[zepumph]

• [ ] Auto imports in typescript files in node code always include the .js suffix. But with require statements we often omit the .js suffix. Should we be consistent, and always include .js like in sim code? Also sometimes I see it imports .ts, probably we never want that.