Resolve "Move GroupFilter from Core"

Closes #33

See merge request !49

Resolve "Set icons for active menu entries"

Closes #32

See merge request !44

Drop sites framework

See merge request !43

Update .gitignore

See merge request !41

Update .prettierignore

See merge request !42

Update tox.ini

See merge request !34

Update .dev-js/package.json

See merge request !35

Update .gitignore

See merge request !37

Update pyproject.toml

See merge request !36

Update pyproject.toml

See merge request !32

Update tox.ini

See merge request !33

Resolve "Adapt to Core 4.0"

Closes #31

See merge request !30

Update tox.ini

See merge request !31

Update .eslintrc.js

See merge request !28

Update pyproject.toml

See merge request !29