dev/core#5370 Fix bug handling soft credits in civi-import

This ensures the userJob is saved at the js layer before the php layer kicks in.
If the js layer save does NOT run first it causes bugs like those
described in https://lab.civicrm.org/dev/core/-/issues/5370

ext/civiimport/ang/crmCiviimport.js

@@ -257,6 +257,7 @@
          * @type {$scope.save}
          */
         $scope.save = (function ($event) {
+          $event.preventDefault();
           $scope.userJob.metadata.entity_configuration = {};
           $scope.userJob.metadata.import_mappings = [];
           _.each($scope.entitySelection, function (entity) {
@@ -280,7 +281,16 @@
               entity_data: entityConfig
             });
           });
-          crmApi4('UserJob', 'save', {records: [$scope.userJob]});
+          crmApi4('UserJob', 'save', {records: [$scope.userJob]})
+            .then(function(result) {
+              // Only post the form if the save succeeds.
+              document.getElementById("MapField").submit();
+            },
+            function(failure) {
+              // @todo add more error handling - for now, at least we waited...
+              document.getElementById("MapField").submit();
+            }
+          );
         });
 
         $scope.load();