feat: schema mixins moved to project level

Resolves circular dependency issues.

src/user/schemas.py

@@ -3,13 +3,9 @@ Pydantic models for the user module
 """
 
 from typing import Optional
-from pydantic import Field, EmailStr
+from pydantic import EmailStr
 
-from src.schemas import CustomBaseModel
-
-
-class UserIDMixin(CustomBaseModel):
-	user_id: int = Field(gt=0)
+from src.schemas import CustomBaseModel, OrgIDMixin
 
 
 class OIDCClaims(CustomBaseModel):
@@ -52,13 +48,7 @@ class UserResponse(CustomBaseModel):
 	groups: Optional[dict[str, list[dict[str, str | int]]]] = None
 
 
-class OrgResponse(CustomBaseModel):
-	org_id: int
-	name: str
-
-
-class UserPostInvitationRequest(CustomBaseModel):
-	organisation_id: int
+class UserPostInvitationRequest(OrgIDMixin):
 	user_email: EmailStr