Add branding configuration and assets for Sepehr tenant

- Created branding.config.ts to define branding settings including app title, support contact information, and working hours.
- Added brandingAssets.ts to import and export logo and login images for the Sepehr tenant.
- Introduced config.ts to specify application type as POS for the Sepehr tenant.

package.json

@@ -56,10 +56,12 @@
     "private": true,
     "scripts": {
         "build": "ng build",
+        "build:sepehr": "ng build --configuration sepehr",
         "build:tis": "ng build --configuration tis",
         "ng": "ng",
         "prestart": "node aspnetcore-https",
         "start": "run-script-os",
+        "start:sepehr": " ng serve --configuration sepehr",
         "start:tis": " ng serve --configuration tis",
         "test": "ng test",
         "watch": "ng build --watch --configuration development"