refactor: remove SalesInvoiceItemsService and update sales invoice handling

- Deleted SalesInvoiceItemsService as it was not implemented.
- Changed variable declaration from `const` to `let` in SalesInvoicesService for sales invoice creation.
- Updated response handling after sending to TSP provider in SalesInvoicesService.
- Renamed payload properties in TspProvider DTOs for clarity.
- Enhanced error handling in SalesInvoiceTspSwitchService for unsupported providers.
- Refactored SalesInvoiceTspService to utilize utility functions for payload building and sending.
- Updated PrismaService to increase connection limit and utilize dynamic options.
- Added new migration scripts to update database schema for sale_invoice_tsp_attempts.
- Introduced utility functions for building payloads and handling responses in sales invoice processing.

src/modules/pos/sales-invoices/sales-invoices.service.ts

@@ -230,7 +230,7 @@ export class SalesInvoicesService {
   }
 
   async create(data: CreateSalesInvoiceDto, posInfo: IPosPayload) {
-    const salesInvoice = await this.sharedSaleInvoiceCreateService.create({
+    let salesInvoice = await this.sharedSaleInvoiceCreateService.create({
       data,
       businessId: posInfo.business_id,
       complexId: posInfo.complex_id,
@@ -240,7 +240,13 @@ export class SalesInvoicesService {
     })
 
     if (data.send_to_tsp) {
-      await this.salesInvoiceTaxService.originalSend(salesInvoice.id, posInfo.pos_id)
+      const providerResponse = await this.salesInvoiceTaxService.originalSend(
+        salesInvoice.id,
+        posInfo.pos_id,
+      )
+      if (providerResponse?.invoice) {
+        salesInvoice = providerResponse?.invoice as any
+      }
     }
 
     return ResponseMapper.create(salesInvoice)