Migrate from CommonJS module system to ESM

[andraskvr]

The ESM module system is getting wider adoption, the problem is that importing an ESM module from a CommonJS module, such as the vscode-inmanta extension itself is not supported (without some hacks).
It should work the other way around, so the proposal is to turn vscode-inmanta to an ESM module as well.

It's also worth to check if using ESM modules VSCode extensions is supported or not.

Some resources:
https://nodejs.org/api/packages.html#packages_determining_module_system
https://redfin.engineering/node-modules-at-war-why-commonjs-and-es-modules-cant-get-along-9617135eeca1

After this the dependabot updates of getPort version 6 can be resumed.