Change log for ZSCALER_VPN

Date Changes
2026-02-10 Enhancement:
- event.idm.read_only_udm.principal.location.city: Newly mapped `ClientCity` raw log field to `event.idm.read_only_udm.principal.location.city`.
- event.idm.read_only_udm.principal.platform: Newly mapped `Platform` raw log field to `event.idm.read_only_udm.principal.platform`.
- Added logic to conditionally populate event.idm.read_only_udm.target.hostname from `Host` or `Hostname` raw fields.
- Added logic to populate event.idm.read_only_udm.principal.hostname from the `Hostname` raw field when `Host` is also present.
- event.idm.read_only_udm.target.hostname: Newly mapped `Host` raw log field to `event.idm.read_only_udm.target.hostname`.
- event.idm.read_only_udm.principal.hostname: Newly mapped `Hostname` raw log field to `event.idm.read_only_udm.principal.hostname`.
- event.idm.read_only_udm.additional.fields: Newly mapped `TimestampConnectionStart`, `TimestampConnectionEnd`, `TimestampCATx`, `TimestampCARx`, `TimestampZENFirstRxClient`, `TimestampZENFirstTxClient`, `TimestampZENLastRxClient`, `TimestampZENLastTxClient`, `TimestampConnectorZENSetupComplete`, `TimestampZENFirstRxConnector`, `TimestampZENFirstTxConnector`, `TimestampZENLastRxConnector`, `TimestampZENLastTxConnector`, `ZENBytesRxClient`, `ZENBytesTxClient`, `ZENTotalBytesRxConnector`, `ZENBytesRxConnector`, `ZENTotalBytesTxConnector`, `ZENBytesTxConnector` raw log fields to `event.idm.read_only_udm.additional.fields`.
- Modified the parser to handle carriage returns and newlines (\r\n) in the raw log message to avoid parsing issues and used `replace` instead of `rename` for `Host` and `Hostname` fields to fix the failing logs. Due to this, the following UDM fields are now being parsed correctly:
- `event.idm.read_only_udm.extensions.auth.type`
- `event.idm.read_only_udm.intermediary[].ip[]`
- `event.idm.read_only_udm.intermediary[].port`
- `event.idm.read_only_udm.metadata.description`
- `event.idm.read_only_udm.metadata.event_timestamp.seconds`
- `event.idm.read_only_udm.metadata.event_type`
- `event.idm.read_only_udm.metadata.log_type`
- `event.idm.read_only_udm.metadata.product_event_type`
- `event.idm.read_only_udm.metadata.product_name`
- `event.idm.read_only_udm.metadata.vendor_name`
- `event.idm.read_only_udm.network.ip_protocol`
- `event.idm.read_only_udm.network.received_bytes`
- `event.idm.read_only_udm.network.sent_bytes`
- `event.idm.read_only_udm.network.session_id`
- `event.idm.read_only_udm.principal.asset.hostname`
- `event.idm.read_only_udm.principal.asset.ip[]`
- `event.idm.read_only_udm.principal.ip[]`
- `event.idm.read_only_udm.principal.location.country_or_region`
- `event.idm.read_only_udm.principal.location.region_latitude`
- `event.idm.read_only_udm.principal.location.region_longitude`
- `event.idm.read_only_udm.principal.port`
- `event.idm.read_only_udm.principal.user.email_addresses[]`
- `event.idm.read_only_udm.principal.user.userid`
- `event.idm.read_only_udm.security_result[].about.labels[].key`
- `event.idm.read_only_udm.security_result[].about.labels[].value`
- `event.idm.read_only_udm.security_result[].action[]`
- `event.idm.read_only_udm.security_result[].description`
- `event.idm.read_only_udm.security_result[].rule_name`
- `event.idm.read_only_udm.security_result[].summary`
- `event.idm.read_only_udm.target.application`
- `event.idm.read_only_udm.target.asset.hostname`
- `event.idm.read_only_udm.target.asset.ip[]`
- `event.idm.read_only_udm.target.ip[]`
- `event.idm.read_only_udm.target.port`
- `event.idm.read_only_udm.target.user.email_addresses[]`
- `event.idm.read_only_udm.target.user.group_identifiers[]`
- `event.idm.read_only_udm.target.user.userid`
2023-06-08 Enhancement -
- Reduced generic percentage.
2023-01-04 Bug-Fix-
- Mapped "LogTimestamp" to "event_timestamp".