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/helpers/setup-server.js

@@ -11,6 +11,8 @@ module.exports = ({ cwd, redisUrl, uploadDir, verbose, env }) => {
   const workerId = parseInt(process.env.JEST_WORKER_ID || "1")
   const redisUrlWithDatabase = `${redisUrl}/${workerId - 1}`
 
+  verbose = verbose ?? false
+
   return new Promise((resolve, reject) => {
     const medusaProcess = spawn("node", [path.resolve(serverPath)], {
       cwd,
@@ -21,6 +23,7 @@ module.exports = ({ cwd, redisUrl, uploadDir, verbose, env }) => {
         COOKIE_SECRET: "test",
         REDIS_URL: redisUrl ? redisUrlWithDatabase : undefined, // If provided, will use a real instance, otherwise a fake instance
         UPLOAD_DIR: uploadDir, // If provided, will be used for the fake local file service
+        CACHE_TTL: 0, // By default the cache service is disabled and 0 means that none of the cache key/value will be stored.
         ...env,
       },
       stdio: verbose