Don't fail when duplicating a test case

src/lib/components/test_cases/TestCaseCompareModal.svelte

@@ -23,27 +23,31 @@
   function duplicateTestCaseAndCloseModal() {
     shared.testCasesIndex = [shared.testCasesIndex[0], shared.testCases.length]
     const duplicatedTestCase = structuredClone(
-      shared.testCases[shared.testCasesIndex[0]],
+      $state.snapshot(shared.testCases[shared.testCasesIndex[0]]),
     )
     duplicatedTestCase.title = `Copie de ${duplicatedTestCase.title}`
     shared.testCases.push(duplicatedTestCase)
 
     const duplicatedEvaluationByName = structuredClone(
-      shared.evaluationByNameArray[shared.testCasesIndex[0]],
+      $state.snapshot(shared.evaluationByNameArray[shared.testCasesIndex[0]]),
     )
     shared.evaluationByNameArray.push(duplicatedEvaluationByName)
 
     const duplicatedInputInstantsByVariableName = structuredClone(
+      $state.snapshot(
         shared.inputInstantsByVariableNameArray[shared.testCasesIndex[0]],
+      ),
     )
     shared.inputInstantsByVariableNameArray.push(
       duplicatedInputInstantsByVariableName,
     )
 
     const duplicatedValuesByCalculationNameByVariableName = structuredClone(
+      $state.snapshot(
         shared.valuesByCalculationNameByVariableNameArray[
           shared.testCasesIndex[0]
         ],
+      ),
     )
     shared.valuesByCalculationNameByVariableNameArray.push(
       duplicatedValuesByCalculationNameByVariableName,

src/lib/components/test_cases/TestCaseSummary.svelte

@@ -288,7 +288,7 @@
     }
     const originalSituation = testCasesCore[situationIndex]
     for (const key in originalSituation) {
-      situation[key] = structuredClone(originalSituation[key])
+      situation[key] = structuredClone($state.snapshot(originalSituation[key]))
     }
   }