NAT-328: updated site name validation by a utils helper func

gso/api/v1/imports.py

 import ipaddress
-import re
 from typing import Any
 from uuid import UUID
 
@@ -16,7 +15,7 @@ from gso.products.product_blocks.router import RouterRole, RouterVendor
 from gso.products.product_blocks.site import SiteTier
 from gso.services import subscriptions
 from gso.services.crm import CustomerNotFoundError, get_customer_by_name
-from gso.utils.helpers import LAGMember
+from gso.utils.helpers import LAGMember, validate_site_name
 
 router = APIRouter(prefix="/imports", tags=["Imports"], dependencies=[Depends(opa_security_default)])
 
@@ -41,12 +40,7 @@ class SiteImportModel(BaseModel):
 
     @validator("site_name", allow_reuse=True)
     def site_name_must_be_valid(cls, site_name: str) -> str:
-        # Accept 3 chapital letters and only one ditigt after capital letters.
-        pattern = re.compile(r"^[A-Z]{3}[0-9]?$")
-        if not bool(pattern.match(site_name)):
-            raise ValueError(f"Enter a valid site name similar looks like AMS, AMS1or LON9. Get: {site_name}")
-
-        return site_name
+        return validate_site_name(site_name)
 
 
 class RouterImportModel(BaseModel):