Add language in sensitivity analysis result csv export (#832)

Signed-off-by: Franck LECUYER <[email protected]>

Author: FranckLecuyer

src/main/java/org/gridsuite/study/server/dto/sensianalysis/SensitivityAnalysisCsvFileInfos.java

@@ -29,4 +29,5 @@ public class SensitivityAnalysisCsvFileInfos {
     private SensitivityFunctionType sensitivityFunctionType;
     private String resultTab;
     private List<String> csvHeaders;
+    private String language;
 }

src/test/java/org/gridsuite/study/server/SensitivityAnalysisTest.java

@@ -371,6 +371,7 @@ private void testSensitivityAnalysisWithRootNetworkUuidAndNodeUuid(final MockWeb
                 .sensitivityFunctionType(SensitivityFunctionType.BRANCH_CURRENT_1)
                 .resultTab("N")
                 .csvHeaders(List.of("h1", "h2", "h3"))
+                .language("en")
                 .build());
 
         mockMvc.perform(post("/v1/studies/{studyUuid}/root-networks/{rootNetworkUuid}/nodes/{nodeUuid}/sensitivity-analysis/result/csv", studyUuid, rootNetworkUuid, UUID.randomUUID())