Change log for IMPERVA_DB

Date Changes
2024-04-09 Enhancement:
- Added "gsubs" to handle invalid JSON characters in logs.
- Mapped "raw-query" to "security_result.detection_fields".
2024-01-21 Enhancement:
- Added a new Grok pattern to parse unparsed logs of format SYSLOG+JSON.
- Mapped "version" to "metadata.product_version".
- Mapped "dest-ip" to "target.ip".
- Mapped "dest-port" to "target.port".
- Mapped "source-ip" to "principal.ip".
- Mapped "source-port" to "principal.port".
- Mapped "db-user" to "principal.user.userid".
- Mapped "os-user" to "principal.user.userid".
- Mapped "protocol" to "network.ip_protocol".
- Mapped "audit-policy" to "security_result.category_details".
- Mapped "server-group", "service-name", "user-group", "raw-query", "parsed-query", "bind-variables", "sql-error", "db-schema-pair.db-name", "db-schema-pair.schema-name", and "objects-list" to "additional.fields".
- Mapped "application-name" to "target.application".
- Mapped "source-application" to "principal.application".
- Mapped "event-id" to "metadata.product_log_id".
- Mapped "event-type" to "metadata.product_event_type".
- Mapped "application-user" to "principal.user.user_display_name".
- Mapped "host-name" to "principal.hostname".
- Mapped "mx-ip", "gw-ip" to "intermediary.ip".
- Mapped "policy-id" and "user-authenticated" to "security_result.detection_fields".
- If "has_principal" is "true" and "has_target" is "true", then set "metadata.event_type" as "NETWORK_CONNECTION".
- If "has_principal" is "true", then set "metadata.event_type" as "STATUS_UPDATE".
2023-07-17 Bug-Fix
- Parsed unparsed raw logs using Grok patterns and 'kv' filters.
- Mapped "srcPort" to "principal.port".
- Mapped "srcIP" to "principal.ip".
- Mapped "dstIP" to "target.ip".
- Mapped "dstPort" to "target.port".
- Mapped "alertSev" to "security_result.severity".
- Mapped "ruleName" to "security_result.rule_name".
- Mapped "category" to "security_result.category".
- Mapped "group" to "target.user.group_identifiers".
- Mapped "dbName" to "target.resource.name".
- Mapped "policyName" to "security_result.detection_fields".
- Mapped "username" to "principal.user.user_display_name".
- Mapped "evntDesc" to "security_result.description".
- Mapped "action" to "security_result.action_details".
2023-02-03 Enhancement
- Mapped "event_name" to "metadata.product_event_type".