feat: finished creating services from controllers, continued implementing entrepreneurServiceApi with some validation

MyINPulse-back/src/main/java/enseirb/myinpulse/model/SectionCell.java

@@ -79,4 +79,8 @@ public class SectionCell {
     public void setModificationDate(LocalDateTime modificationDate) {
         this.modificationDate = modificationDate;
     }
+
+    public Project getProjectSectionCell() {
+        return projectSectionCell;
+    }
 }