Connect - Relation on FE Importer (#13213)

Done : 
- Relation connect on FE Importer
- Remove templating on SpreadsheetMatchedColumn type
- Remove useless files on import
- Remove AvailableFieldsForImport type + Update SpreadsheetImportField
type and SpreadsheetImportFieldOption


To test : 
- Try import opportunities on Apple wk 
[using this
file](https://github.com/user-attachments/files/21233720/Test.import.-.opportunities-sample.csv)


closes : https://github.com/twentyhq/core-team-issues/issues/1090

packages/twenty-server/src/engine/twenty-orm/entity-manager/workspace-entity-manager.ts

@@ -1558,7 +1558,9 @@ export class WorkspaceEntityManager extends EntityManager {
             const connectFieldName = connectQueryConfig.connectFieldName;
 
             throw new TwentyORMException(
-              `Expected 1 record to connect to ${connectFieldName}, but found ${recordToConnectTotal}.`,
+              `Expected 1 record to connect to ${connectFieldName}, but found ${recordToConnectTotal} with conditions: ${JSON.stringify(
+                connectQueryConfig.recordToConnectConditionByEntityIndex[index],
+              )}.`,
               TwentyORMExceptionCode.CONNECT_RECORD_NOT_FOUND,
             );
           }