In usercard add a checkbox to keep child card

[freddidierRTE]

The objective is to offer the user the choice to keep existing response, if any, when editing a card

• The option appears on edition mode if there is already one or more child cards
• The option appears only if the state (in config.json) has the parameter userCard.keepChildCardsVisible set to true (default value is false)
• This checkbox is checked by default
• The label of the checkbox shall be "keep existing responses"
• The label in french shall be "Conserver les réponses existantes"

Implementation

• Like for severity, create a class keepchildCardForm.ts in ui/main/src/app/business/view/userCard/keepchildCardsForm
• Use setInputVisibility in UserCardUIControl to set field visibility
• Add unit test in ui/main/src/app/business/view/userCard/userCard.view.spec.ts (see "Get ChildCard for preview " and "Send card tests"
• Adjust or add an existing cypress test to check the option is present and the checkbox selected and send card
• Add new config option keepChildCardsVisible in src/test/api/karate/businessconfig/getABusinessconfig.feature