Update twenty-front commands (#4667)

# This PR

- Moves dev and ci scripts to the `project.json` file in the
twenty-front package
- Adds a project.json file in the root of the project with the main
start command that start both twenty-server and twenty-front
applications concurrently
- Updates the script command of the root project with the start:prod
command (replacing the start command which will be used in dev with the
help of nx)
- Add a start:prod command in the twenty-front app, replacing the start
command (now used for dev purpose)

Issue ref #4645 

@charlesBochet @FelixMalfait please let me know how can I improve it

---------

Co-authored-by: Thaïs Guigon <guigon.thais@gmail.com>

package.json

@@ -270,6 +270,7 @@
     "danger": "^11.3.0",
     "dotenv-cli": "^7.2.1",
     "drizzle-kit": "^0.20.14",
+    "esbuild": "^0.20.2",
     "eslint": "^8.53.0",
     "eslint-config-next": "14.0.4",
     "eslint-config-prettier": "^9.1.0",
@@ -329,7 +330,7 @@
   },
   "version": "0.2.1",
   "scripts": {
-    "start": "cross-env FORCE_COLOR=true concurrently -n \"twenty-server,twenty-front\" -c \"bgBlue.bold,bgGreen.bold\" \"yarn nx start twenty-server\" \"yarn nx start twenty-front\""
+    "start:prod": "cross-env FORCE_COLOR=true concurrently -n \"twenty-server,twenty-front\" -c \"bgBlue.bold,bgGreen.bold\" \"yarn nx start twenty-server\" \"yarn nx start twenty-front\""
   },
   "workspaces": {
     "packages": [