Fix dependency issues in the monorepo #570
Description
Explanation
The monorepo currently suffers from dependency issues.
These issues occur, for example, when a package upgrade in one package, affects the tests / snapshots in another package.
This makes it hard to add new packages and/or update existing packages.
The ideal situation would be that every package specifies their dependencies correct. At the moment, some package do not have all their dependencies listed. Normally, this would be a problem but since node automatically checks parent directories for node_modules, these missing dependencies are now hoisted from the dependencies of other packages.
When someone upgrades the dependency in that package, it will affect the tests/build in this package.
Technical decisions
Each package should correctly specify their dependencies and the versions of their dependencies.