feat(medusa): BatchJobStrategy and loaders (#1434)

* add batch job strategy interface

* update plugin loaders

* remove comment

* make map async

* ensure that only one of each strategy is registered

* register strategies plural

* add identifier and batchType properties

* extend batch job strategy identification method

* initial test

* update loaders to accomodate different ways of accessing batch job strategies

* identifier batch type field

* redo merge in plugins

* update interface and load only js files

* use switches instead of elif

* remove comments

* use static properties for strategy registration

* update tests

* fix unit tests

* update test names

* update isBatchJobStrategy method

* add check for TransactionBaseService in services for plugins

* update interfaces export

* update batchjob strategy interface with a prepare script

* update loaders

* update batchjob strategy interface

* remove everything but public interface methods from batchJobStrategy

* add default implementation to prepareBathJobForProcessing

* remove unused import

packages/medusa/src/api/middlewares/error-handler.ts

@@ -11,7 +11,12 @@ const INVALID_REQUEST_ERROR = "invalid_request_error"
 const INVALID_STATE_ERROR = "invalid_state_error"
 
 export default () => {
-  return (err: MedusaError, req: Request, res: Response, next: NextFunction) => {
+  return (
+    err: MedusaError,
+    req: Request,
+    res: Response,
+    next: NextFunction
+  ) => {
     const logger: Logger = req.scope.resolve("logger")
     logger.error(err)
 

packages/medusa/src/api/routes/admin/price-lists/create-price-list.ts

@@ -8,7 +8,8 @@ import {
 } from "class-validator"
 import PriceListService from "../../../../services/price-list"
 import {
-  AdminPriceListPricesCreateReq, CreatePriceListInput,
+  AdminPriceListPricesCreateReq,
+  CreatePriceListInput,
   PriceListStatus,
   PriceListType,
 } from "../../../../types/price-list"