Some cleanup
More cleanup
Finish cleanup of commit 1dd351dcd090f2c8b8f0a3a3da3291f5f1134252

This includes refactoring the checks in ParametersStorage (at import
time), moved into the relevant classes directly.
code style
Some factorizing of default values
Fix issues with using backendApiUrl from parametersStorage. Add todos.
Add todo
Add todos to finish checking commits