core: Do not throw a runtime exception when no solver is installed
Context
One can still browse the dictionaries if no solver is installed, it's a bit harsh to throw a runtime exception.
Let's allow to start the application without solver installed and present a proper error message when trying to list solvers or use them.
What has changed?
Main Changes
core
- Impact the "list-solvers" and the "solve" use-case implementations
tests
- Add a test with non solver deployed
- Fix a scenario with wrong description