Simplified custom select process

src/app/calculators/solveur/config.json

src/app/calculators/verificateur/config.json

src/app/formulaire/definition/form-fixedvar.ts

src/app/formulaire/definition/form-macrorugo-compound.ts

src/app/formulaire/definition/form-parallel-structures.ts

src/app/formulaire/definition/form-solveur.ts

src/app/formulaire/definition/form-verificateur.ts