Change log for CISCO_TACACS

Date Changes
2026-01-29 Enhancement:
- Added new grok pattern to parse new log format.
- event.idm.read_only_udm.principal.user.userid: Newly mapped `common_username` raw log field with `event.idm.read_only_udm.principal.user.userid` UDM field.
- event.idm.read_only_udm.target.application: Newly mapped `common_service` raw log field with `event.idm.read_only_udm.target.application` UDM field.
- event.idm.read_only_udm.principal.ip: Newly mapped `tacacs_remote_address` raw log field with `event.idm.read_only_udm.principal.ip` UDM field.
- event.idm.read_only_udm.network.session_id: Newly mapped `tacacs_acct_session_id` raw log field with `event.idm.read_only_udm.network.session_id` UDM field.
- event.idm.read_only_udm.principal.nat_ip: Newly mapped `common_nas_ip_address` raw log field with `event.idm.read_only_udm.principal.nat_ip` UDM field.
- event.idm.read_only_udm.additional.fields: Newly mapped `tacacs_privilege_level`, `tacacs_acct_flags`, `tacacs_auth_source`, `tacacs_authen_method`, `tacacs_authen_service`, `tacacs_authen_type`, `tacacs_enforcement_profiles`, `tacacs_request_type`, `tacacs_session_log_timestamp`, `common_request_timestamp`, `tacacs_acct_timestamp`, `tacacs_authen_action` raw log field(s) with `event.idm.read_only_udm.additional.fields` UDM field.
- event.idm.read_only_udm.metadata.event_type: If `has_principal` is true, updated to `STATUS_UPDATE`.
- event.idm.read_only_udm.metadata.event_type: If `has_principal_user` is true, updated to `USER_UNCATEGORIZED`.
2024-11-07 Enhancement:
- Added support to handle SYSLOG+KV logs.
2024-09-19 Enhancement:
- Added support for new log format.
2022-08-09 Bug fix -
-Modified mapping for the field 'Networkdevicename' from 'prinicipal.asset.hostname' to 'intermediary.hostname'.
2022-03-22 Newly created parser.