validation: add checksum validation of Swedish organization numbers

using mod10

Author: alexanbj

.changeset/tall-symbols-enjoy.md

@@ -0,0 +1,5 @@
+---
+"@obosbbl/validation": patch
+---
+
+add checksum validation of Swedish organization numbers. Previously we only checked the length of the number.

packages/validation/src/se.ts

@@ -81,7 +81,7 @@ export function validateOrganizationNumber(
     value = stripFormatting(value);
   }
 
-  return /^\d{10}$/.test(value);
+  return /^\d{10}$/.test(value) && mod10(value);
 }
 
 type NationalIdentityNumberFormat = 'short' | 'long';