feat(medusa): Performance improvements of Carts domain (#2648)

**What**

I have created a new method on the cart service which is `addLineItems`, allowing a user to add one or multiple items in an optimized way. Also updated the `generate` method from the line item service which now also accept a object data or a collection of data which. Various places have been optimized and cache support has been added to the price selection strategy.

The overall optimization allows to reach another 9000% improvement in the response time as a median (Creating a cart with 6 items):

|   | Min (ms)  | Median (ms)  | Max (ms)  | Median Improvement (%)
|---|:-:|---|---|---|
| Before optimisation  | 1200  | 9999 | 12698  |  N/A
| After optimisation | 63  | 252  | 500  | 39x
| After re optimisation | 56 | 82  | 399  | 121x
| After including addressed feedback | 65 | 202  | 495  | 49x

FIXES CORE-722

integration-tests/api/__tests__/admin/draft-order/draft-order.js

@@ -26,7 +26,7 @@ describe("/admin/draft-orders", () => {
   beforeAll(async () => {
     const cwd = path.resolve(path.join(__dirname, "..", "..", ".."))
     dbConnection = await initDb({ cwd })
-    medusaProcess = await setupServer({ cwd, verbose: true })
+    medusaProcess = await setupServer({ cwd })
   })
 
   afterAll(async () => {

integration-tests/api/__tests__/admin/draft-order/ff-tax-inclusive-draft-order.js

@@ -29,7 +29,6 @@ describe("[MEDUSA_FF_TAX_INCLUSIVE_PRICING] /admin/draft-orders", () => {
     const [process, connection] = await startServerWithEnvironment({
       cwd,
       env: { MEDUSA_FF_TAX_INCLUSIVE_PRICING: true },
-      verbose: false,
     })
 
     dbConnection = connection