ESLint Warnings

[danielpeintner]

With #1424 we introduced some new eslint warnings.

At the moment, npm run lint shows a huge list of warnings. I suggest turning them off and look at them one by one (so that we can fix one by one)
see https://github.com/eclipse-thingweb/node-wot/blob/master/eslint.config.mjs

• n/no-missing-import (see ESLint Warning n/no-missing-import #1428)
• n/no-extraneous-import (see ESLint Warning n/no-extraneous-import #1437)
• n/no-unpublished-import (see refactor: activate eslint n/no-unpublished-import #1438)
• n/no-unsupported-features/node-builtins (see ESLint Warning n/no-unsupported-features/node-builtins #1439)
• n/no-deprecated-api (see refactor: avoid deprecated api #1436)
• n/no-process-exit (see Turn off warning/error for process exit #1505)
• no-unused-private-class-members (see refactor: activate rule no-unused-private-class-members #1434)
• prefer-const (see chore: activate "prefer-const" eslint error #1432)
• unused-imports/no-unused-vars (see refactor: removing unused variables #1435)
• extraneous-dependencies/no-extraneous-dependencies (see ESLint Warning extraneous-dependencies/no-extraneous-dependencies #1442)
• @typescript-eslint/no-floating-promises (see refactor: activate rule @typescript-eslint/no-floating-promises #1446)
• @typescript-eslint/no-require-imports (see refactor: activate eslint @typescript-eslint/no-require-imports #1443)
• @typescript-eslint/no-empty-object-type (see refactor: activate eslint @typescript-eslint/no-empty-object-type #1441)
• @typescript-eslint/prefer-nullish-coalescing (see refactor: activate eslint typescript-eslint/prefer-nullish-coalescing #1440)