Clean up and align all package.json files in root folder and subfolders

[christian-kreuzberger-dtx]

Right now we install different packages, dependencies, etc... in the root folder of this repo vs. the sub-task folders.

In addition, Microsoft docs state that it is possible to install dependencies on root-level of the extension, and re-use them within each task (this needs to be tried out though; probably need to include node_modules in the manifest).

Definition of done

• [ ] package.json on root-folder is more stricter regarding versions (e.g., using ~ vs. ^)
• [ ] package.json in all sub-tasks should have the same dependencies and versions, at least where possible
• [ ] If possible, keep all needed dependencies on root folder package.json
• [ ] Research whether we need/should add package-lock.json to the repo

[christian-kreuzberger-dtx]

already merged