Change log for TRIPWIRE_FIM

Date Changes
2023-06-21 Enhancement:
- Added gsub to handle CEF format logs.
2023-06-07 Enhancement:
- Added a Grok pattern to handle CEF formatted logs.
2022-06-14 Bug-Fix: - Added a new grok to parse "HKEY_" type logs without space between regestry_key and value.
- Added validation check for target_hostname or target_ip prior to mapping of event_type to NETWORK_CONNECTION.
- Added null check for username prior to mapping to udm.