feat(customer): admin CRUD endpoints (#6232)

**What**

- GET /customers/:id
- POST /customers/:id
- DELETE /customers/:id
- POST /customers

Including workflows for each.

packages/customer/src/migrations/Migration20240124154000.ts

@@ -6,6 +6,7 @@ export class Migration20240124154000 extends Migration {
     this.addSql(
       'create table if not exists "customer" ("id" text not null, "company_name" text null, "first_name" text null, "last_name" text null, "email" text null, "phone" text null, "has_account" boolean not null default false, "metadata" jsonb null, "created_at" timestamptz not null default now(), "updated_at" timestamptz not null default now(), "deleted_at" timestamptz null, "created_by" text null, constraint "customer_pkey" primary key ("id"));'
     )
+    this.addSql('alter table "customer" alter column "email" drop not null;')
     this.addSql(
       'alter table "customer" add column if not exists "company_name" text null;'
     )

packages/customer/src/services/customer-module.ts

@@ -8,6 +8,7 @@ import {
   CustomerTypes,
   SoftDeleteReturn,
   RestoreReturn,
+  CustomerUpdatableFields,
 } from "@medusajs/types"
 
 import {
@@ -110,24 +111,24 @@ export default class CustomerModuleService implements ICustomerModuleService {
 
   update(
     customerId: string,
-    data: Partial<CustomerTypes.CreateCustomerDTO>,
+    data: CustomerUpdatableFields,
     sharedContext?: Context
   ): Promise<CustomerTypes.CustomerDTO>
   update(
     customerIds: string[],
-    data: Partial<CustomerTypes.CreateCustomerDTO>,
+    data: CustomerUpdatableFields,
     sharedContext?: Context
   ): Promise<CustomerTypes.CustomerDTO[]>
   update(
     selector: CustomerTypes.FilterableCustomerProps,
-    data: Partial<CustomerTypes.CreateCustomerDTO>,
+    data: CustomerUpdatableFields,
     sharedContext?: Context
   ): Promise<CustomerTypes.CustomerDTO[]>
 
   @InjectTransactionManager("baseRepository_")
   async update(
     idsOrSelector: string | string[] | CustomerTypes.FilterableCustomerProps,
-    data: Partial<CustomerTypes.CreateCustomerDTO>,
+    data: CustomerUpdatableFields,
     @MedusaContext() sharedContext: Context = {}
   ) {
     let updateData: CustomerTypes.UpdateCustomerDTO[] = []