handles Traefik multilayer routing (#1629)

* handles Traefik multilayer routing

* Add test log for traefik multilayer routing

* Fix assertions and add a test

* feat(traefik-logs): Add support for multi-layer routing with Root/Intermediate/Leaf routers

- Parse Traefik's multi-layer routing chains (X levels of routers)
- Extract root router (first in chain), intermediate routers (middle), and leaf router (last)
- Use Traefik's official terminology: Root → Intermediate → Leaf
- Ensure consistent behavior between CLF and JSON log formats
- Add test cases for extended router chains (4 routers)
- Provide full chain in traefik_router_name_full for both formats
- Expose breakdown via meta fields: traefik_router_name_root, traefik_router_name_intermediate, traefik_router_name_leaf

Signed-off-by: Laurence <laurence.jones@live.co.uk>

* fix: dont set router twice if no leaf

* fix(traefik-logs): Only populate root router when chain exists and allow blank routers

- Set traefik_router_name_root to empty string for single/standalone routers
- Only populate root when there's an actual hierarchy (leaf exists)
- Update TRAEFIK_ROUTER pattern to accept blank values ("-")

* fix: router may be -

* fix: make the parser simpler

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Signed-off-by: Laurence <laurence.jones@live.co.uk>
Co-authored-by: Laurence <laurence.jones@live.co.uk>

Author: ook