Resolve "Use isort"

Description

isort added to pyproject.toml and devcontainer. isort run on all python files. Also sort all imports in js-files.

Notes to review (code/docs/QA)

Since vscode setting:

"editor.codeActionsOnSave": {
    "source.organizeImports": true
}

is not available per language, I also applied sorting to all js files.

Related issues

Closes #2239 (closed)