Support for complex metric types and other toggles like guardrail cutoffs

[A-Rindone]

Support for complex metric types (percentile, etc.)
Add guardrail cutoffs

Some of this is limited by what we expose in our APIs today.

Complex dbt features (e.g., intricate filters, certain derived metric types not listed) or specific Eppo features (e.g., threshold, conversion, retention operations, funnel metrics) may require adjustments to the mapping logic in mapper.py or may not be fully supported yet.