[Enhancement] Add support for dnsmasq-dhcp for PFSense integration

[daviddreher2]

Updated ingest pipelines for PFSense DHCP component to support logs from dnsmasq DHCP server, currently only supports deprecated ISC DHCP server logs

Changes:

Default Pipeline

• added dnsmasq-dhcp to the list for the drop processor
• added dnsmasq-dhcp to the list for the dhcp pipeline

DHCP Pipeline

• added Grok pattern to extract dnsmasq log fields to the correct field names
• added a gsub operator to replace dnsmasq-dhcp with dhcpd in the event.provider field to ensure dashboards work correctly

Checks:

• Confirmed Grok pattern extracts correctly
• Confirmed dashboard loads data correctly
• Checked pipeline for errors

Validations:

• configure PFSense/OPNsense to use dnsmasq for DHCP
• Send dnsmasq logs to Elastic agent integration via syslog
• confirm data

Partially resolves issue #17264

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[mergify]

⚠️ The sha of the head commit of this PR conflicts with #17375. Mergify cannot evaluate rules on this PR. ⚠️