feat(medusa,core-flows,types): add cart <> tax integration workflows + steps (#6580)

what:

- adds tax lines to cart when item operations take place

RESOLVES CORE-1821
RESOLVES CORE-1822
RESOLVES CORE-1823
RESOLVES CORE-1824

packages/tax/src/providers/system.ts

@@ -20,6 +20,7 @@ export default class SystemTaxService implements ITaxProvider {
           name: r.name,
           code: r.code,
           line_item_id: l.line_item.id,
+          provider_id: this.getIdentifier(),
         }))
       })
 
@@ -31,6 +32,7 @@ export default class SystemTaxService implements ITaxProvider {
           name: r.name,
           code: r.code,
           shipping_line_id: l.shipping_line.id,
+          provider_id: this.getIdentifier(),
         }))
       })
     )

packages/tax/src/services/tax-module-service.ts

@@ -6,6 +6,7 @@ import {
   InternalModuleDeclaration,
   ModuleJoinerConfig,
   ModulesSdkTypes,
+  TaxRegionDTO,
   TaxTypes,
 } from "@medusajs/types"
 import {
@@ -14,16 +15,14 @@ import {
   MedusaContext,
   MedusaError,
   ModulesSdkUtils,
-  arrayDifference,
   isDefined,
   isString,
   promiseAll,
 } from "@medusajs/utils"
-import { TaxProvider, TaxRate, TaxRegion, TaxRateRule } from "@models"
+import { TaxProvider, TaxRate, TaxRateRule, TaxRegion } from "@models"
 import { entityNameToLinkableKeysMap, joinerConfig } from "../joiner-config"
-import { TaxRegionDTO } from "@medusajs/types"
-import { uniqueRateReferenceIndexName } from "../models/tax-rate-rule"
 import { singleDefaultRegionIndexName } from "../models/tax-rate"
+import { uniqueRateReferenceIndexName } from "../models/tax-rate-rule"
 import { countryCodeProvinceIndexName } from "../models/tax-region"
 
 type InjectedDependencies = {