[FR] Revisit Filter Schema for Removal or Extension

[Mikaayenson]

Summary

Related to #3753

We need to look at the class Filter Schema and determine if we want to fully extend to support all the other Extended classes or leave the schema open. Historically the meta schema was left open, then we added stricter support for TRADE use cases. Now that we're supporting DAC, we need to consider if we want to leave it open or fully support the filter schemas implemented in Kibana.