Don't display unmatched columns in csv import (#6037)

Adding a toggle so that, by default, we don't see dozens of fields but
only the field we matched, during the data validation step in csv export

<img width="785" alt="Screenshot 2024-06-26 at 13 25 36"
src="https://github.com/twentyhq/twenty/assets/6399865/ae558eb5-7461-4bc8-a836-ecff8b6d0dff">

packages/twenty-front/src/modules/spreadsheet-import/tests/mockRsiValues.ts

@@ -1,4 +1,5 @@
 import { defaultSpreadsheetImportProps } from '@/spreadsheet-import/provider/components/SpreadsheetImport';
+import { Columns } from '@/spreadsheet-import/steps/components/MatchColumnsStep/MatchColumnsStep';
 import { Fields, SpreadsheetOptions } from '@/spreadsheet-import/types';
 import { sleep } from '~/utils/sleep';
 
@@ -88,6 +89,33 @@ const fields = [
   },
 ] as Fields<string>;
 
+export const importedColums: Columns<string> = [
+  {
+    header: 'Name',
+    index: 0,
+    type: 2,
+    value: 'name',
+  },
+  {
+    header: 'Surname',
+    index: 1,
+    type: 2,
+    value: 'surname',
+  },
+  {
+    header: 'Age',
+    index: 2,
+    type: 2,
+    value: 'age',
+  },
+  {
+    header: 'Team',
+    index: 3,
+    type: 2,
+    value: 'team',
+  },
+];
+
 const mockComponentBehaviourForTypes = <T extends string>(
   props: SpreadsheetOptions<T>,
 ) => props;