feat(fortigate): add golden configuration baseline and fortios parser

[michaelelrom]

Summary

• Adds the fortios Config Manager parser: built on the cisco-ios lexer template (whitespace-delimited words, quoted strings preserved), plus a # comment rule to correctly skip the #-prefixed metadata header lines (#config-version=..., #buildno=...) FortiOS always emits at the top of a config export.
• Adds the FortiGate - Simple golden configuration tree (deviceType: fortios), covering:
  • Admin session timeout, disallowing HTTPS admin-redirect disable
  • Password policy (status + minimum length)
  • NTP sync to a named server
  • Syslog forwarding
  • Disallowing a wide-open trusthost1 0.0.0.0 0.0.0.0 management ACL
  • Disallowing telnet/HTTP management access on port1
• Ships with no device bindings.
• Updates Fortinet/FortiGate/README.md with Configuration Parsers and Golden Configurations sections (TOC, Contents table, asset docs).

Test plan

• Parser and tree created live via the Config Manager API on a running Itential Platform instance.
• Confirmed the template parses into the correct nested config-spec structure (config block → set lines) with correct evalMode/severity per line (required/error, disallowed/error, ignored, informational).
• Confirmed the tree integrates correctly with the platform's compliance batch engine (ran a live compliance batch against it).
• Reviewer: import both files into a test instance and confirm compliance runs against a real or sample FortiGate config as expected.