feat: custom installments (#4)

* feat: add database schema

* feat: add custom installments payload

* chore: migrations

prisma/migrations/20241031023932_add_name_for_custom_installments/migration.sql

@@ -0,0 +1,2 @@
+-- AlterTable
+ALTER TABLE "QuotationPaySplit" ADD COLUMN     "name" TEXT;

prisma/schema.prisma

@@ -1195,6 +1195,7 @@ model QuotationPaySplit {
   id String @id @default(cuid())
 
   no     Int
+  name   String?
   amount Float
 
   quotation   Quotation? @relation(fields: [quotationId], references: [id], onDelete: Cascade)