Change log for ISC_DHCP

Date Changes
2024-11-27 Bug-Fix:
- Changed mapping for "host" from "principal.hostname" to "target.asset.hostname".
- Mapped "pid" go "target.process.pid".
- Mapped "process" to "target.application".
- Mapped "via" to "principal.ip" and "principal.asset.ip".
- Mapped "ipaddress" to "principal.ip" and "principal.asset.ip".
- Mapped "macaddress" to "principal.mac" and "principal.asset.mac".
2024-01-29 Enhancement:
- Added Grok patterns to parse dropped logs.
2023-12-29 Enhancement:
- Added Grok patterns to match new log format.
- If "network.dhcp.ciaddr" is not set, set "metadata.event_type" to "STATUS_UPDATE".