refactor: calculator configuration: remove defaultNodeType property

src/app/calculators/bief/config.json

src/app/calculators/courberemous/config.json

src/app/calculators/regimeuniforme/config.json

src/app/calculators/sectionparametree/config.json

src/app/formulaire/definition/config-parser.ts

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

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

src/app/formulaire/elements/fieldset-template.ts