NAT-328: updated validation site name by an utils method

gso/workflows/site/create_site.py

-import re
-
 from orchestrator.forms import FormPage
 from orchestrator.targets import Target
 from orchestrator.types import FormGenerator, State, SubscriptionLifecycle, UUIDstr
@@ -13,7 +11,12 @@ from gso.products.product_blocks import site as site_pb
 from gso.products.product_blocks.site import LatitudeCoordinate, LongitudeCoordinate
 from gso.products.product_types import site
 from gso.services.crm import customer_selector
-from gso.utils.helpers import validate_country_code, validate_ipv4_or_ipv6, validate_site_fields_is_unique
+from gso.utils.helpers import (
+    validate_country_code,
+    validate_ipv4_or_ipv6,
+    validate_site_fields_is_unique,
+    validate_site_name,
+)
 
 
 def initial_input_form_generator(product_name: str) -> FormGenerator:  # noqa: C901
@@ -56,14 +59,8 @@ def initial_input_form_generator(product_name: str) -> FormGenerator:  # noqa: C
             by an optional single digit (0-9).
             """
             validate_site_fields_is_unique("site_name", site_name)
-            pattern = re.compile(r"^[A-Z]{3}[0-9]?$")
-            if pattern.match(site_name):
-                return site_name
-            else:
-                raise ValueError(
-                    "Enter a valid site name. It must consist of three uppercase letters (A-Z) followed by an optional"
-                    " single digit (0-9)."
-                )
+            validate_site_name(site_name)
+            return site_name
 
     user_input = yield CreateSiteForm