creating new radius and tacacs data classes (#815)

* updating radius and tacacs data classes for new changes

* fix static

* fix static

* make vpn vpn id optional

* sub class

* match with parent class

* match with parent class

* match with parent class

* snake case

* description

* src checks

* src checks

* src checks

catalystwan/dataclasses.py

@@ -453,13 +453,22 @@ class RadiusServer(DataclassBase):
     address: str = field(metadata={FIELD_NAME: "address"})
     auth_port: int = field(metadata={FIELD_NAME: "authPort"})
     acct_port: int = field(metadata={FIELD_NAME: "acctPort"})
-    vpn: int = field(metadata={FIELD_NAME: "vpn"})
-    vpn_ip_subnet: str = field(metadata={FIELD_NAME: "vpnIpSubnet"})
+    vpn: Optional[int] = field(metadata={FIELD_NAME: "vpn", "description": "required field  < 20.16"})
+    vpn_ip_subnet: Optional[str] = field(metadata={FIELD_NAME: "vpnIpSubnet", "description": "required field  < 20.16"})
     key: str = field(metadata={FIELD_NAME: "key"})
     secret_key: str = field(metadata={FIELD_NAME: "secretKey"})
     priority: int = field(metadata={FIELD_NAME: "priority"})
 
 
+@define(frozen=True)
+class ExtendedRadiusServer(RadiusServer):
+    """
+    Extended RADIUS server with additional fields.
+    """
+
+    source_vpn: Optional[int] = field(default=None, metadata={FIELD_NAME: "sourceVpn"})
+
+
 @define(frozen=True)
 class TenantRadiusServer(DataclassBase):
     """
@@ -479,13 +488,22 @@ class TacacsServer(DataclassBase):
 
     address: str = field(metadata={FIELD_NAME: "address"})
     auth_port: int = field(metadata={FIELD_NAME: "authPort"})
-    vpn: int = field(metadata={FIELD_NAME: "vpn"})
-    vpn_ip_subnet: str = field(metadata={FIELD_NAME: "vpnIpSubnet"})
+    vpn: Optional[int] = field(metadata={FIELD_NAME: "vpn", "description": "required field  < 20.16"})
+    vpn_ip_subnet: Optional[str] = field(metadata={FIELD_NAME: "vpnIpSubnet", "description": "required field  < 20.16"})
     key: str = field(metadata={FIELD_NAME: "key"})
     secret_key: str = field(metadata={FIELD_NAME: "secretKey"})
     priority: int = field(metadata={FIELD_NAME: "priority"})
 
 
+@define(frozen=True)
+class ExtendedTacacsServer(TacacsServer):
+    """
+    Extended TACACS server with additional fields.
+    """
+
+    source_vpn: Optional[int] = field(default=None, metadata={FIELD_NAME: "sourceVpn"})
+
+
 @define(frozen=True)
 class TenantTacacsServer(DataclassBase):
     """